Glossary of Terms

Here at SGS Engineering, we understand that there's often plenty of jargon or interchangeable terms associated with many of our products. We want our product range to be as accessible as possible, so we've but together this handy Glossary of Engineering Terms that should help you get to grips with some of the language often thrown around these product ranges. Whether you're looking for help getting to grips with a gas strut, generator, air compressor, a home or garden power tools, hydraulic jacks or garage equipment - you've come to the right place! Jump to:




























Abrasive disk

Categories: Air Tools, Power Tools Consumable accessories that are fitted on to various power tools for cutting, grinding sanding, etc. Also see:

Accessory bit

Categories: Power tools Use an accessory bit with your drill or driver. Drill bits are used for drilling holes. Driving bits are used for driving fasteners. Simply loosen the chuck of your drill, insert the shank of the accessory bit and firmly tighten. Also see:

(see: Chuck, Shank)

Adjustable shoe

Categories: Power Tools A feature of a power saw where you can move the shoe that holds the blade, backwards or forwards, exposing more or less of the blade in the process. The shorter the blade length the easier it is to control. Longer blades can cut deeper into materials.

Adjustable / variable force gas strut

Categories: Gas Struts This variety of gas strut comes per-set to the maximum force a gas strut can take and then can be vented to the desired force by the end user. These struts are ideal for when the desired force is unknown, one off jobs and prototyping. Also see:

After cooler

Categories: Air Compressors A heat exchanger that cools the air discharged from an air compressor. The discharged air/ condensate will have less moisture, thereby improving the air flow in the system.

Air cooled engine

Categories: Generators, Compressors A cooling method that circulates air around the warm parts of an engine. Ideal for heavy duty applications.

Air dryer

Categories: Compressors A device that can be added to some air compressors. An air dyer removes moisture from compressed air, typically accomplished by cooling air through a refrigerator or dessicant bed.

Air filter

Categories: Compressors Separates and removes particulate matter, moisture, lubricant or fuel from air.

Air Leakage

Categories: Compressors Small leaks can create a huge loss in output and cost a small fortune in the long run. For example, a 0.75mm dia. air leakage is a loss of 1.6 CFM or an extra 300W of energy. A 1.4mm dia. hole is a loss of 6.5 CFM or 1100W! Replace faulty equipment quickly to avoid mounting costs and a lack of performance.

Air regulator

Categories: Compressors Used for controlling the amount of pressure received from an air compressors tank. Also see:

Air tank

Categories: Compressors Holds compressed air until it is used by an air tool, etc. Sometimes called an "Air Receiver". Also see:

Air line oil

Categories: Compressors Lubricant, blended from solvent refined, napthenic base oils and additives. Use with air line lubricators for keeping your air system and tools well lubricated. Also see:

Air stapler

Categories: Air Tools A pneumatic staple machine, similar to a nail gun. Ideal for furniture upholstery. Comes in various gauges for varying sizes of staples. Also see:

Alternating current (AC)

Categories: Generators, SPX  Electric current that increases to a maximum positive, falls back to zero, and then to the maximum negative. In a 60 hertz AC power supply the cycle is repeated 60 times.

Ampere (Amp)

Categories: Generators A unit of measurement: electric current flow. One ampere (amp) will flow when one volt is applied across a resistance of one ohm.

Atmospheric pressure

Categories: Compressors The ambient pressure for a specific place and altitude.

Angle grinder

Categories: Power Tools A hand held power tool used with a variety of disk attachments for grinding, cutting, polishing etc. Often used to cut tiles and stone, trim metal piping or similar DIY and construction tasks. The tool gets it's name from the fact that the head is mounted at a slight angle to the drive shaft. Also see:

Automatic Transfer switch (ATS)

Categories: Generators An ATS system will automatically switch from main utility power to standby, back up power from a generator, in the case of a power cut out. Also see:

(see: Transfer Switch)

Auger bit

Categories: Power Tools A type of drill bit used to bore (create deep holes) in wood or another material. Also see:

Auxiliary fuel pump

Categories: Generators A special pump to move fuel from a remote storage location to a generator or engine.

Axle stands

Categories: Garage Also called jack stands, an axle stand supports a vehicle so it can be worked under without the need of a vehicle ramp. You should never work under a vehicle supported by a hydraulic jack alone. Axle stands come in pairs and are rated for a certain capacity that should not be exceeded. Also see:


Ball-bearing sliders

Categories: Garage Used in SGS tool chest drawers, hard steel balls run in precision troughs, providing an incredibly stable and easy to use drawer action, even with heavier loads. Also see:

Ball socket

Categories: Gas Struts A common type of end fixing used with gas struts. Ball sockets clip onto a bracket with a ball stud on it and enables a gas strut to be mounted at an angle with-out side loading. Available in steel and plastic. Also see:

Ball stud

Categories: Gas Struts A common type of end fixing used with gas struts. These joints use a spherical bearing that connects to a control arm to allow for lots of movement around a central point. Ball studs are recommended for most applications as they allow the gas strut to be mounted at any angle. Available in steel and plastic. Also see:


Categories: Garden The long arm of a chainsaw that that holds and drives the chain cutting blade. Also see:

Bed hinge mechanism

Categories: Gas Struts Bed mechanism consist of a pair of hinges to mount to the bottom and top of a bed together and a pair of gas struts to provide assistance raising and lowering the bed, usually for extra storage. Also see:

Bevel cut

Categories: Power Tools A cut made at an angle to a work piece, usually done with a mitre saw (however some jig saws have a bevel feature). Also see:


Categories: Power Tool The metal accessory that goes into a drill's tip (or chuck). There are specific bits for drilling and driving. Also see:

Black oxide bits

Categories: Power Tools High speed steel drill bits with a black oxide finish which is created by a combination of chemicals and heat during the manufacturing process. Because of this finish, they have a higher resistance to rust and stay sharper longer. Use for general purpose drilling. Also see:

Blade clamp

Categories: Power Tools The part of a saw that holds the blade in place. Most blade clamps are tool-less and spring loaded. Always unplug (or remove the battery) from a saw before you try to change the blade, or adjust a blade clamp. Always check that blade is properly secured and not loose in the clamp. Never work with a loose blade!

Blade shank

Categories: Power Tools The section of the blade that is held within the blade clamp. You should double check what type of blade shank your saw takes before you purchase a new blade. Also see:


Categories: Gas Struts The hinged metal canopy covering the engine of a vehicle, sometimes supported by a gas strut. Also see:


Categories: Gas Struts The hatch at the rear of a vehicle, sometimes called a tailgate. The hatch is opened and closed for loading or unload a vehicle. Gas struts are often used to help lift a car boot open and close with minimal effort. Also see:

Bottle jack

Categories: Garage A type of hydraulic lifting jack where the piston ram extends from a cylinder. They are compact and can be rated for huge loads. Also see:


Categories: Gas Struts Used to mount a gas strut to an application. Also see:

Brad-point bit

Categories: Power Tools A type of drill bit that has three small points at the tip that prevents the bit from moving when you start drilling. Use these bits for precise drilling. Also see:


Categories: Generators, Compressors A conductor (usually made of carbon, i.e. carbon brushes) serving to keep an electrical connection between the stator and rotor within a machine, such as a generator.


Car gas struts

Categories: Gas struts Also know as car gas springs or tailgate struts. Nitrogen filled, cylinder and piston designed as a like-for-like replacements for original car gas struts. The purpose of a car gas strut is to assist with supporting the weight of a heavy hatch. Gas struts can be found all around a car, including the boot, tailgate, bonnet, doors and windows. Always match the part numbers from your original struts with SGS equivalents. Also see:

CE Marked

Categories: General "CE" is the abbreviation for the French "Conformité Européene" - or European Conformity. All SGS products fully conform to, or exceed, relevant European standards and therefore are CE marked.


Categories: Gas struts The measurement of gas strut taken between the centre of one end fixing to the centre of the other end fixing when fully extended. Also see:

Circuit breaker

Categories: Generators A thermal switch that turns off if too high a current is passing through it. All SGS, Hyundai and Stephill generators have circuit breakers.

Compound mitre saw

Categories: Power Tool A power tool for wood working, that is capable of cutting compound angles. These saws can cut angles of up to 45 degrees, either side in relation to a vertical fence. The blade can be angled or tilted in relation to the machine base. Also see:

Compression ratio

Categories: Compressors Discharge pressure to intake pressure ratio.

Compressor oil (AC 2068)

Categories: Compressors ISO VG 68 oil for reliable and effective lubrication for compressors. Also see:

Constant speed control

Categories: Compressors A control method for a continuously running air compressor that matches the air flow to the varying demands of the air system.

Continuous load

Categories: Generators The output a generator can can maintain for long periods of time, assuming maintenance and servicing is kept up with. Not all generators are suitable for continuous use. Also see:

Cordless power tool

Categories: Power Tools A type of power tool that has it's own source of power, usually a rechargeable lithium-ion battery, Also see:


Categories: Garden The cutting blade of a chain saw (or similar tool) that fits on a chain saw bar. Also see:

Chain file

Categories: Garden A safety feature of a chainsaw allowing you to quickly disengage the chainsaws engine and stop the chain rotating. Also see:

Chain file

Categories: Garden A rounded file for sharpening a blunted chainsaws chain. A chain file is provided with every SGS chainsaw in the toolkit. Also see:

Chain oil

Categories: Garden Lubricating oil for chainsaws (and similar tools). Improves chain life, safety and reduces chain drag. Density @ 15°C 0.880 / Viscosity @ 40°C 130 cSt / Viscosity @ 100°C 14.5 cSt Also see:

Chainsaw/ chain saw

Categories: Garden A mechanically driven cutting tool that uses teeth on a rotating chain, moving round the edge of a bar - usually used for cutting lumber. Also see:

Check valve

Categories: Air Compressors, Hydraulics A specific valve type that allows flow in only one direction.


Categories: Power Tools The cylinder that opens and closes the jaw of a drill that allows you to fit a drill bit. (see: Bit).

Chuck jaw

Categories: Power Tools The section at the very tip of a drill that holds a bit in place.

Chuck key

Categories: Power Tools A tool designed for loosening and tighten the chuck of a drill for you can inset an accessory bit. Many modern drills are "Tool-less Chuck" or "Automatic Spindle Locking" meaning you don't require any additional tools to loosen or tighten the chuck - it can be done by hand.

Closed height

Categories: Garage The measurement of hydraulic jack, going from it's lowest point to it's highest point when the jack is fully decompressed. The measurement can be used to make sure a hydraulic jack will fit under your vehicle. Purchase a hydraulic jack that has a closed height less than the ground clearance of your vehicle. Also see:


Categories: Power Tools On a drill the clutch is usually located just behind the chuck. The drill clutch lets you adjust the torque setting of the drill.

Coarse grit

Categories: Power Tools The coarser the grit of your sand paper the rougher the texture is. Coarse sand papers have a lower grit rating (40 or 80 grit). Use coarse grit paper is for removing more stock material and gives a rougher finish.

Compound cut

Categories: Power Tools A combination of a Mitre cut and a Bevel cut. This is a useful cut for doing crown moldings around a door or a window. Simply set both a mitre level and bevel angle on your mitre saw.


Categories: Garage A mechanics creeper is a low profile frame supported by caster wheels used for working underneath vehicles comfortably. Also see:

Cross cut

Categories: Power Tools A simple cut made across the grain of the wood.

Curve cut

Categories: Power Tools Normally done with a jig saw or a hand saw, a curved line in a piece of material. Might be useful for wooden decorations. Use a high speed setting and apply only a light amount of pressure as you go around your cut line. If the cut is at a particularly sharp angle you may wish to make relief cuts to help with the blades performance.

Certificate of conformity (CoC)

Categories: Gas Struts, General Sometimes known as a Declaration of Conformity, A formal declaration by a manufacturer, that the product to which it applies meets all relevant requirements of all product safety directives applicable to that product. It is a sign that a product has been designed and constructed for compliance with relevant essential requirements, and has been through the appropriate conformity assessment processes. You will normally find a CoC for SGS products in the back of an instruction manual (available on each individual product page). You can find a Certificate of Conformity for SGS Gas Struts here. If you can't find a certificate for your product you can contact SGS for a copy of the certificate.

Cubic feet per minute (CFM)

Categories: Compressors A unit of measurement of volumetric air flow displaced by an air compressor under a certain condition. CFM can be thought of as the capacity of an air compressor. The higher the CFM of an air compressor the more tools you'll be able to run. Also see:

Cut line indicator

Categories: Power Tools Notches in the front of the base of a saw that show you where your blade will go. Some cut line indicators are more accurate than other so make sure to get familiar with how your saw works and performs.


Categories: Compressors The series of steps that a compressor with unloading performs; 1) fully loaded, 2) modulating (for compressors with modulating control), 3) unloaded, 4) idle.


Categories: Gas Struts The part of a gas strut that the rod protracts into, containing oil, nitrogen gas and pressure. The cylinder provides the pressure for the rod. The fatter end of a gas strut. (see: Cylinder End, Rod)

Cylinder diameter

Categories: Gas Strut A measurement of the thickness of the cylinder of a gas strut. The cylinder diameter is dependant on the rod diameter.


Categories: Gas Struts The end fatter end of a gas strut, typically fitted with an end fixing such as a ball socket or eyelet.


Data Sheet (dB)

Categories: Gas Struts A technical data sheet for SGS gas struts can be found here.

DeciBel (dB)

Categories: Generators, Compressors, Power Tools, SPX One-tenth of a Bel (B). A unit of measurement for noise. The hearing threshold (i.e. the lowest noise a human can hear)is 0dB. The threshold of pain (i.e. the loudest noise a human can ear can tolerate) is 140dB. This measurement should help you choose a machine that is appropriate for your working environment.

Design service

Categories: Gas Struts SGS Engineering offer a free gas strut design service which will enable you to lift almost any flap, panel or hatch with a controlled motion. To take advantage of the design service you can fill out the form here. The free design service is not available in conjunction with any other offer.

Diamond saw blade

Categories: Power Tools A saw accessory with a matrix of diamond chips, ideal for cutting ceramics, concrete and masonry.

Diesel generator

Categories: Generator Diesel generators are more suited to regular use and commercial applications. Many diesel generators are portable and can be fitted with wheel kits. The cost of running and maintaining a diesel generator can be significantly less than a petrol alternative. Also see:

Direct current (DC)

Categories: Generators Electric current that flows in one direction only. DC current is produced by chemical process (such as in a battery) or by an electromagnet.

Discharge pressure

Categories: Compressor The pressure of the air output, measured in PSI or bar.

Displacement (Volume)

Categories: Compressor The displacement of a compressor is the theoretical capacity of a compressor, i.e. the swept volume of a cylinder multiplied by the number of compression's per minute. This is expressed in CFM (Cubic Feet Per Minute).

Drain cock

Categories: Compressors A stopper used to release accumulated moisture/liquids from an air compressor tank.

Drain valve

Categories: Compressors A special type of valve used to release accumulated moisture/liquids from an air compressor tank. These valves can be manual, float or electronic.


Categories: Power Tools A power tool with two modes or more, capable of boring holes (drilling) and fixing fasteners (driving). Also see:

Drill bit

Categories: Power Tools An accessory for a drill used for making holes in various materials. For help choosing the right drill bit see:

Driving / Screw-driving bit

Categories: Power Tools An accessory for a drill or driver used for driving fasteners, such as screws, into various materials via a series of interchangeable bits. They come in a variety of shapes such as Philips, Slotted, Torx etc. For help choosing the right driver bit see:

Dust collection

Categories: Power Tools A popular feature of high end sanders and saws that use a vacuum to pick up waste material. Dust collection helps to keep the work piece visible, improving the finish of your cut / sanded material.

Drawer liners

Categories: Garage Used in SGS tool chest drawers. Heavy duty, non-slip mats, designed to stop tools slipping around when opening and closing the drawers. Also see:


Edge guide

Categories: Power Tools An accessory for a saw. It fits to the nose of a saw and helps to make straight cuts in materials.

End fixing

Categories: Gas Struts Typically attached to each end of a gas strut for mounting to an application. SGS end fixings come in a huge array of sizes, as well as plastic and stainless steel. (see: Ball Sockets, Ball Studs, Eyelets, Clevis Folk) Also see:

Engine crane

Categories: Garage Also known as an engine hoist, an engine crane is a repair and maintenance tool used to remove or install engines and similar components. Engine cranes have caster wheels so you can move the part once you've removed it from a vehicle. (see: Engine stand / transmission stand, Load Leveller) Also see:

Engine displacement (CC)

Categories: Compressors, Generators, Garden, General The volume swept by the pistons inside a reciprocating engine, in one complete movement. Measured in cubic centimetres (cc or cm3), litres (l), or cubic inches (CID).

Engine speed

Categories: Generators, Compressors The speed at which a the engine flywheel moves, measured in revolutions per minute (RPM)

Engine stand / transmission stand

Categories: Generators, Compressors Can be used to secure and work on engines and similar vehicle parts, once they've been removed. (see: Engine cranes) Also see:

Electric start

Categories: Generators, Garden A reliable starting mechanism that doesn't require moving parts for firing to the spark-plug Also see:

Epoxy paint

Categories: Gas Struts, Compressors A type of protective coating used to make a product chemical or solvent resistant. SGS gas struts and many medical compressors have epoxy coatings for adding protection.


Categories: Gas Struts A common type of end fixing with a round hole in it, often found on a gas strut. Used for mounting a gas strut onto a a bolt or pin. Eyelets are mounted "offset" whereas Clevis Fork fixings are mounted "in-line". Available in steel or plastic. See the full range of SGS eyelets here. (see: Clevis Folk)


Factory edge

Categories: Power Tool The uncut edge of wood or material bought from a shop. Usually, this side of the material is already square.


Categories: Power Tool Hardware that keeps two or more materials together, such as screws and bolts.

Fine grit

Categories: Power Tool Referring to smoother sandpaper, fine grit is less coarse paper for finer finishing and less stock removal. The higher grit rating a piece of sand paper has the smoother it is (typical values include, 220 to 300 grit).


Categories: Power Tool The condition of your wood or material after having been cut or sanded. The finer the finish, the smoother it will be to touch.

Finish nailer

Categories: Air Tools, Power Tool A pneumatic nailer suitable for small finishing nails. Ideal for furniture or similar. Also see:

Fitting guide

Categories: Gas Struts A fitting guide is provided with every set of vehicle gas struts purchased You can see a copy of the gas strut fitting guide here.

Fixed force gas strut

Categories: Gas Struts A type of gas strut sold with a set Newton force of between 50 - 2500N. SGS can set the force as required, however once these gas struts have been shipped, the force cannot be altered or adjusted by the end user. Also see:


Categories: Gas Struts Measured in Newtons (N), describes the potential pushing strength a gas strut can exert when correctly mounted. SGS can add Force to a strut, however Force can not be removed unless you have an adjustable gas strut.

Framing nailer

Categories: Air Tools, Power Tool A pneumatic nailer that drives large framing nails. Also see:

Free Air Delivered

Categories: Compressor  This measurement describes the volume of air taken in to a compressor. Therefore accurately describes the usable volume of air. Typically this is expressed as FAD/CFM.

Flush cutting

Categories: Power Tool Cutting a piece of material or a fastener like a screw, so is lies flat against the surface of another material. Flush cuts are useful for tidying up rough work.

Flush screw

Categories: Power Tool A screw where the head is level with the material it is fixed to. Useful for moldings, furniture and high quality finishes.

Fly lead

Categories: Generators A special socket that converts one type of output to another, for example a 16A power supply to a 13A power supply. It is safe to use a series of fly leads, for example a typical set up might be: Generator -> 32A Lead to Socket 16A -> 16A Lead to 13A Socket -> Electrical item. Also see:


Categories: Power Tools, Air Tools Sometimes called Idle RPM. The speed a tool moves without any resistance, (i.e. when the trigger is pulled but not working against a material). Normally measured in RPM.


Categories: Generators The numbers of cycles (vibrations) per second of an alternating current. (see: hertz)

Fuel injector

Categories: Generators The component that introduces a metered amount of fuel to the combustion chamber of an engine.

Fuel line

Categories: Generators The tubes that move fuel to and from an engine.

Fuel ratio / fuel mixture

Categories: Garden Two-stroke garden tools require you to mix petrol with 2-stroke oil. The individual fuel ratio of every garden tool can be found in the product manuals. Strimmers 40:1. Chainsaws: 25:1. Hedge Trimmers: 40:1. Also see:


Categories: Generators A protective device in an electrical circuit. It is made up of a conductor that melts and breaks the electrical circuit if a current of electricity passes through a system that is higher than the system's rated value.


Gear switch

Categories: Power Tools The switch, normally on the top of a power tool, that lets you choose between the highest speed, or the highest torque. (see: Torque)


Categories: Generators Converts mechanical energy into electrical energy. Also see:

Grass strimmer / trimmer

Categories: Garden A mechanically driven garden tool, using a flexible monofilament line instead of a blade. Usually this tool is used on grass and plants on steep or uneven ground. Also see:

Grid power

Categories: Generators Commercial power from the electric grid (National Grid - UK). Generators can be used to power almost anything in a situation when grid power is compromised. Also see:


Categories: Generators A connection between an electric circuit and either the earth or a conducting body that acts in place of the earth. Most portable petrol generators are self grounding, including the SGS Engineering SPG Series.


Heat sink

Categories: Generators, Compressors Something that conducts heat away from electrical devices in order to cool key components.

Heavy duty

Categories: Garage, Generators, Compressors, General Designed to withstand hard wear within a products normal usage.


Categories: Generators A unit of measurement representing  cycles per second.

High-lift jacks

Categories: Garage A hydraulic vehicle jack that has a larger than average lifting range, designed for vehicles that sit higher from the ground, like 4x4s and vans. Also see:

Horsepower / Brake Horsepower (HP)

Categories: Generators, Compressors, Garden, SPX A unit measuring power / the rate at which work is done, normally of an engine or motor. The higher the horsepower the more powerful the engine or motor.

High-Volume, Low-Pressure(HVLP)

Categories: Spray Guns  Spray guns with this type of material transfer give you better, more consistent coverage than conventional spray guns, and with minimal messy over-spray.


Inverter generator

Categories: Generator Inverter generators use pure sine wave technology to create a "clean" energy output suitable to sensitive electrical items like a TV, computer, phone or anything else with a microprocessor. Inverters are often used for leisure applications, such as camping. Also see:



Categories: Power Tools A reusable guide made for your saw. You can make your own jig or simply use a piece of straight wood you have lying around.


Keep side

Categories: Power Tools The side of the material you're working on that you intend to use.


Categories: Power Tools The thickness of a saw blade.

Keyless chuck

Categories: Power Tools A type of chuck that requires no addition tools to tighten or loosen, meaning you can replace your drill bits with ease.


Categories: Power Tools, Garden Tools When a power tool is forced back towards the user, normally at speed. Particularly apparent with tools like chainsaws and power-saws. Kickback can cause serious damage to the operator if it catches them by surprise. Tips for minimizing kickback:

  • If possible, clamp the material you're working on
  • Keep a firm, two-handed grip on your power tool at all times
  • Keep a stable, firm stance when working with a power tool


Lag screw

Categories: Power tools A heavy duty fastener used for structural support in serious wood working projects. You might use these screws when building a deck or putting up a stud wall.

Leaf blower

Categories: Garden Also known as a blower. A mechanically driven garden tool designed to move leaves, grass clippings and garden debris, making it easier to remove. Also see:


Categories: Compressors, Generators, Garden An unintended loss of compressed air (air compressor) or oil/fuel (generator, garden tool).

Laser guide

Categories: Power Tools A useful feature of many power saws. A laser guide shows where the blade will land before making a cut. Make more accurate cuts, quicker with a laser guide on your jig saw / mitre saw.

Line pressure gauge

Categories: Compressors, Hydraulics Reads the amount of pressure in the hose that's powering an air tool or piece of hydraulic equipment.

LPG generator

Categories: Generators Dual fuel generators that can run off either petrol or liquefied petroleum gas (LPG). LPG generators are cheaper to run than petrol, better for the environment and ideal for leisure users who already have access to LPG gas bottles - such as campers. Also see:

Lithium-ion Battery

Categories: Power tools Lithium batteries are fast charging, long running and fade-free, making them an ideal power source for power tools. They are the natural successor to older Ni-Cad batteries. Also see:

Load leveler

Categories: Garage An accessory for an engine crane, designed to help remove and replace engines / motor-parts at difficult angles. Also see:

Locking tube

Categories: Gas struts An optional extra on many gas struts, a locking tube keeps a gas strut extended, even if the gas strut was to fail. To release you need to pull the locking mechanism on the locking tube. A locking tube will also act as a protection cover. Also see:

Long-reach jacks

Categories: Garage A hydraulic jack with a greater than average reach, meaning wider vehicles and vehicles with more difficult to reach jacking points, are easily accessible.

Low oil shutdown

Categories: Generators A popular generator feature that will automatically cut off the engine if it runs low on fuel. This feature helps to protect the generator and avoid accidental damage.

Low profile jack

Categories: Garage A hydraulic jack designed for vehicles with very low ground clearance.


Masonry bits

Categories: Power Tools Drill bits with a carbide tip used to drill holes in brick, mortar, block and concrete. Also see:

Medical compressor

Categories: Compressor Specialist air compressors for clinical, dental, medical applications. Typically oil-less and coated in epoxy paint for cleaner air outputs. Also see:

Mitre cut

Categories: Power Tools A cut made at an angle, usually with a Mitre Saw. Often used for skirting boards, door trim, base boards and moldings. Also see:

Mitre saw

Categories: Power Tools A power tool named after a mitre joint. Used to make cuts across the length of a piece of timber at various angles. Also see:


Categories: Compressors, Power Tools, Hydraulics, General A machine thats supplies motive power to another device. Normally when we talk about a motor, we're talking about electrical power. An engine will normally describe a liquid fuel powered motor.

Mounting instructions

Categories: Gas struts Mounting instructions are sometime provided when a gas strut is designed for a new application via the SGS design service. Mounting instructions are specific for every application and emailed after a custom gas strut is shipped. These instructions may carry an additional charge.

Multi-stage compressor

Categories: Compressor A compressor that has two or more stages operating in series.


Newtons (N)

Categories: Gas Struts A measurement of force (SI), named after Isaac Newton. One Newton is the force required to accelerate one kilogram of mass at the rate of one metre per second squared in a the direction of the force applied. Gas struts will be pressurized to a specific Newton value depending on the weight and nature of an application. The Newton force of your gas strut can normally be found printed on the gas strut itself - for example, 250 N.

NGK Spark Plug

Categories: Garden A highly reliable brand of spark plugs, found in SGS petrol garden tools.

Ni-cad battery (nickel cadmium)

Categories: Power Tools Older battery powered tools were powered by Nickel Cadmium batteries - or "Ni-Cad" batteries. Compared to Lithium-ion alternatives, Ni-Cad power tools take longer to charge and have a fade effect, meaning as the battery decreases, so does the power of your tool.

Nitride plate steel

Categories: Gas Struts A heat-treated type of steel that diffuses nitrogen into the metals surface, creating a hardened surface. The SGS standard range of gas struts are made from Nitride plate steel. (see: Stainless-steel 316)


Categories: Gas Struts NitroLift is a gas strut brand designed and manufactured by SGS Engineering in the UK. Also see:

Nut Driver Bit

Categories: Power Tools A type of drill/driver bit for driving nuts, bolts and hex head fasteners. Also see:

(see: Bit)


ONE+ (One Plus)

Categories: Power Tools The Ryobi series of 18V battery powered power tools. Each lithium-ion battery is capable of being used with any of the tools in the range (50+ home and garden power tools). Batteries are available with capacities of between 1.3Ah and 5.0Ah batteries. Also see:


Categories: Power Tools Simply, this term means to move back and forth. Many different power tools use an oscillating head in order to cut or sand. Also see:

(see: Oscillation rate, Oscillating multi-tool)

Oscillating multi-tool

Categories: Power Tools A versatile power tool that uses an oscillating head to cut, saw, sand and scrape depending on the accessory you've chosen. The "Swiss army knife" of the power tool world. Also see:

(see: Oscillation, Oscillation rate)

Oscillation angle

Categories: Power Tools The angle telling you how far the a tool moves from side to side per oscillation. The higher the oscillation angle the more aggressive the tool. For example, a multi-tool with an oscillation angle of 2.5° will have a greater level of precision than a tool with an angle of 3 degrees. On the other hand the tool with 3 degrees of oscillation will cut quicker. Also see:

(see: Oscillation, Oscillating Multi-Tool)

Orbital sander

Categories: Power Tools A woodworking power tool. A specialist sander that has an orbital head for a fine finish. Also see:

Oscillation rate

Categories: Power Tools Measured in oscillations per minute (OPM), the higher the oscillation rate, the more power the tool has and the more work the tool will do. Also see:

(see: Oscillation, Oscillating Multi-Tool)

Oil Free / oil-less Compressor

Categories: Compressor A type of air compressor that has no oil in the compression chamber for lubrication, cooling or sealing. They require little maintenance and reduce the amount of contaminants in the displaced air flow, making them ideal for medical or food processing applications. Also see:

Overhead valve (OHV)

Categories: Generators, Garden A type of engine configuration where the valves are above the combustion chamber in the cylinder head, instead of to the side of the piston within the engine block. The benefits of an OHV layout includes;

    • Smoother fuel mixture
    • Quicker and more complete exhaust
    • Better thermal balance (which helps for improved emissions, decreased oil usage and increased engine life)


Part numbers

Categories: Gas Struts Sometimes referred to as OEM number. We recommend finding the part number printed on the side of your old gas strut to ensure you order the correct struts for your car or application. You can use the search bar on any page of the website to look up the correct gas strut for your replacement gas strut. If your gas strut doesn’t have a part number or you would like assistance selecting a new gas strut for your vehicle please contact our sales team or call 01332 576 850 Mon-Sat, 8am to 5pm Also see:

Percussion drill

Categories: Power Tools A drill with an on/off hammer option for drilling small holes into masonry. You can also drill woods and metals in the same way you can with a standard drill driver Also see:

Pilot hole

Categories: Power Tools Use a pilot hole to prevent wood from splitting when you're drilling or driving. Make your hole with a small drill bit a little way through the piece you're working on. Now you're ready to use a larger drill bit for the actual hole you want or drive the appropriate fastener. Also see:

Petrol generator

Categories: Generator Petrol generators are inexpensive portable power solutions designed primarily for back-up and hobbyists. They range from 1KVA to around 10KVA Also see:


Categories: Compressors, Hydraulics, Garage Equipment, General A short cylinder or disc that fits within a tube that can move up and down against a liquid or gas. Pistons are used in reciprocating engines, reciprocating pumps, gas compressors and pneumatic & hydraulic cylinders, and many other similar mechanisms. The motion of a piston going up and down is usually converted into rotary motion via the means of a connecting rod.

Pivoting shoe

Categories: Power Tools A feature of a power saw that allows you to move the saw back and forth while you're cutting.

Pointless (CDI) ignition

Categories: Garden A system of engine ignition that uses a high voltage pulse from the trigger to the the coil, via a CDI unit. The coil amplifies the pulse from the CDI unit, giving you more reliable ignition.

Powder coating

Categories: Power Tools A protective coasting applied electro-statically as a dry powder. It's purpose is to enhances the hardness and durability of painted metals, such as SGS tool chests.

Pressure switch

Categories: Compressors A feature that automatically senses the change in pressure and adds or decreases air in the tank accordingly.

Pressure washer

Categories: Garden Also known as a power washer. A mechanically powered high-pressure, mechanical water sprayer. Often used to remove dirt, mold, paint, grime and mud from buildings, concrete surfaces and vehicles. Many can be customised with accessories such as flat surface cleaners and sand blasting kits.

Professional / industrial air compressor

Categories: Compressors A high duty cycle air compressor designed for demanding every day use. Always make sure your air compressor has a high enough CFM output for your tool. Also see:


Categories: Power Tools Also known as a "thickness planer", or even a "thicknesser". A power tool designed for woodworking that uses a single cutting head to shave (plane) timber to a parallel depth and thickness. Also see:

Plunge cut / Pocket cut

Categories: Power Tools A cut made on the inside of a work piece with no edge to start from. You might use this type of cut for cutting out a hole for a wall socket or a floor vent. Reciprocating saws and multi-tools are ideal for this type of cutting work. (see: Reciprocating saw, Oscillating Multi-Tool)


Categories: Compressor  This is the force / power in the compressed air system. This will be expressed in PSI or bar. The maximum pressure is important because if you have too low a pressure your air equipment will not work correctly. If the pressure is too high it will quickly wear out your air equipment. Failing that, make the equipment dangerous to use. Most compressors will allow you to regulate the working pressure for the equipment you're using.


Categories: Compressors, Hydraulics Compressors - The component that compresses the air and pushes it into the tank. Hydraulics - The component of a hydraulic system that builds pressure to move hydraulic liquid around a system.

Purge / air purge

Categories: Compressors, Garage, Hydraulics The removal of undesired liquid or gas from a system. Also see:


Categories: Air Compressors, Generators, SPX The number of complete voltage and/or current sine waves generated per 360 electrical degrees. Each phase requires a complete set of windings. Generators will normally either supply a single-phase or three-phase power supply. For help choosing a single phase or three phase generator have a look at our Generator Buying Guide. Air Compressors will require either a single-phase or three-phase power supply. For help choosing the right phase compressor, have a look at our Air Compressor Buying Guide.

Portable generator set

Categories: Generators Anything set on wheels, skid, truck or railroad car (but not self propelled) that is designed to supply electric power. Small portable generators are often petrol driven.

Power factor

Categories: Generators The ratio of the actual electrical power in an AC circuit to the product of the RMS (root-mean-square) values of current and voltage. The difference between the two is caused by reactance in the circuit and represents power that does no useful work.


Categories: Compressors, Hydraulics Force per unit area - normally measured in bar or PSI. Air tools will have specific working pressure requirement which you need to make sure you air compressor can produce before you make a purchase.

Protection cover

Categories: Gas struts An optional extra on many gas struts, a protection cover keeps a gas strut free from moisture, dirt and grease, prolonging the life of a strut. Protection covers are particularly useful in dirty environments. A locking tube will also act as a protection tube. Also see:



Ratchet / farm jacks

Categories: Garage A type of hydraulic jack suited to lifting, pushing or spreading machinery, 4x4s, tractors, wire fences, posts, etc. Also see:

Rail approved generator

Categories: Generators Generators Network Rail approved for usage in and around railways. SGS Engineering is one of only a few UK suppliers of Rail Approved generators Also see:

Rated AC output

Also know as, Rated Power Categories: Generators The net electric output a generator can provide on a continuous basis. The rated output of a generator  takes into account some head room. Where as Rated AC Output can be thought of as average power usage, Maximum Rated Power is the very highest output a particular generator can produce. When you're choosing a generator ensure the output requirements are the same as or below the Rated AC Output of the generator. Have a look at our  Generator Buying Guide for more help. Also see:

Retaining pin / ball stud pin

Categories: Gas Struts A simple pin clip used for securing ball sockets or stud. Supplied with all ball sockets and studs sold by SGS. Replacement pins can be purchased here.


Categories: Gas Strut Also know as piston rod. The protruding ram/arm of a gas strut. The rod sits inside the cylinder of a gas strut when it is compressed. (see: Rod end, Rod diameter, Cylinder, Stroke, Piston Rod)

Rod diameter

Categories: Gas Strut A measurement of the thickness of the rod on a gas strut. The rod diameter is dependant on the cylinder diameter.

Rod end

Categories: Gas Strut The thinnest end of a gas strut. The side of a gas strut the rod protrudes from. Typically fitted with an end fixing such as a ball socket or eyelet.

Rotary screw compressor

Categories: Compressor A compressor which utilizes inter-meshing rotors to trap air and compress it to a high pressure. Rotary screw compressors can be run at lower temperatures for 24 hours per day, 365 days a year.

Re-gassing service

Categories: Gas Struts SGS Engineering have developed a unique system of re-pressurizing old gas struts for significant savings over purchasing new replacements. The process is greener, cheaper and guaranteed for one-month, but will often last for years. You can get a quote for re-gassing a strut here.


Categories: Compressor Another word for an air tank on a compressor. The larger the receiver the the more gas can be stored under pressure.

Reciprocating compressor

Categories: Compressor A common type of compressor in which the compressing element is a piston moving in a reciprocating motion within a cylinder.

Relief cut

Categories: Power Tools A cut made on the waste side of the wood that lets you move a saw more easily around a curve you're cutting.

Resistance (Ohm)

Categories: Generators A unit of measurement representing resistance. One volt causes a current on one ampere to flow through a resistance of 1 Ohm.

Revolutions per minute (RPM)

Categories: Generators, Power Tools, Garden, Air Tools, SPX The amount of times something (usually and engine or motor) rotates in a single minute. Generators will usually come with 3000 RPM engines or 1500 RPM engines. As a rule, the lower the RPM the longer life you can expect from your generator and the less maintenance you should expect to do.  Have a look at our  Generator Buying Guide for more help. Power and Air Tools will often have Free Load Speed measured in RPM, giving you an indication of the power of the motor the tool uses. The higher the RPM the more affective a tool.

Rip cut

Categories: Power Tools A simple cut that goes with the grain of the wood, for example when you're cutting a long piece of wood for a frame.

Right angle drill

Categories: Power Tools A specialist power drill that has the chuck pointing at a right angle to the shaft. Very useful for drilling at difficult angles and getting into spaces a conventional drill cannot. Also see:

Rocket lift jacks

Categories: Garage A hydraulic jack that typically requires less pumps to reach full extension, usually using dual pistons or an advanced hydraulic ram design.


Categories: Generators The rotating part of a generator (or motor). (see: Stator)

Rotary hammer drill

Categories: Power Tools A specialist power drill for drilling larger holes in masonry and concrete. Many rotary hammer drills have chisel settings. Also see:



Categories: Garage The top most section of a hydraulic jack which will touch the underside of a vehicle as you lift it. Some saddles can used with jacking pads to protect the underside of you car. Others have special ports to you attach accessories like a jacking beam. The larger the diameter of a saddle the more evenly spread the lifting force will be, thereby minimizing the possibility of damage to the underside of a vehicle.

Semi-professional compressor

Categories: Compressor A compressor ideal for a serious hobbyists or undemanding professional applications. Lower duty cycles than a professional compressor, but powerful enough for most air tools. See CFM output to be sure you're choosing the right compressor for the job at hand. Also see:


Categories: Garden A protective sheath for a chainsaw chain and bar. Allows for the safe transportation and storage of a chainsaw.

Safety valve

Categories: Compressor, Hydraulics A type of valve which limits pressure by releasing some pressurized liquid or gas.

Scroll cut

Categories: Power Tools A type of cut for making shapes and curves in a material, often used for making wooden ornaments. The most intricate the shape, the harder this cut is to perform. Use a high cutting speed and a scrolling blade with a high TPI.

Self-tapping screws

Categories: Power Tools A type of fastener that makes its own hole when it's driven - used for sheet metals.


Categories: Power Tools The part of an accessory drill or driving bit that goes into the drills chuck. Typical shank types are round, 3-flat, reduced and hex type.


Categories: Power Tools The part of a saw that rests against the material you are cutting. The shoe should always be flat against the material you're working on. It reduces the vibration of the saw and gives you enhanced control

Short circuit

Also know as, A short or s/c Categories: Generators An unintentional electrical fault where the passage of the current takes an undesirable path, rather than reaching the desired output. A short circuit can be dangerous, outputting thousands of times the normal operating current in just a millisecond.  Fuses, circuit breakers, or overload protection all help to protect against excessive current. Many electrical faults are wrongly described as a "Short circuit". (see: Fuses, Circuit breakers, Overload protection)

Single phase

Categories: Generators, Air Compressors, SPX A single-phase generator (or single-phase alternator) produces a single, continuously alternating voltage. These generators can be used to generate power in single-phase electric power systems. Single phase generators tend to have a maximum output wattage of under 40 kVA. Have a look at our  Generator Buying Guide for more help. A single-phase Tool such as an air compressor, will have a single-phase engine or motor and require a single-phase power source. (see: Three-Phase, Phase)

Single stage compressor

Categories: Compressor A single stage compressor has one or more cylinder. If there is more than one, both cylinders are the same size. It is not recommended for operating pressures exceeding 100 PSI / 7 bar except if the tool will be used intermittently.

Shade bit / paddle bit

Categories: Power Tools A large, flat drill bit used for making larger holes in a material. Also see:

(see: Bit)

Sliding compound mitre saw

Categories: Power Tools A woodworking power tool that is capable of cutting compound angles. In addition it has a sliding function that allows it to cut wider pieces of timber than a standard drop saw.

Spark plug

Categories: Generators, Garden A component part designed to fire the explosive mixture in an engine. Used in all petrol garden tools and generators.


Categories: Gas Struts A large supplier of gas struts. SGS can manufacture gas struts that are direct replacements for Stabilus original parts, that require no additional modification for fitting. Also see:


Categories: Power Tools A chemical used to colour or dye your wood. (see: Rotor)

Stainless steel 316

Categories: Gas Struts A steel alloy containing chromium. Ideal for corrosive or sterile environments such as medical or marine settings. 316 stainless steel has no electromagnetic field and poses no fire risk. (see: Nitride-plate steel) Also see:


Categories: Generators That static part of a generator (or motor). (see: Rotor)

Start/stop control

Categories: Compressors A system where an air supply is matched to the demand of the system by starting and stopping the compressor accordingly.

Stripped screws

Categories: Power Tools If you've "stripped a screw" the head of the screw has been deformed by the spinning driving bit. Stripped screw heads can be very hard to get out.


Categories: General, Gas Struts The stroke of a hydraulic component refers to the overall distance the cylinder/rod will travel to perform it's work (lifting or moving an object). From a fully closed to a fully open position, the total length of travel of the cylinder is its stroke. If a cylinder travels 500mm from its fully closed position to a fully open position, we say that the cylinder has a stroke of 500mm. It's often stated that stroke is the overall length of a cylinder, however in reality it is only a measure of how far the piston will extend from its external tube.

Sub flush screw

Categories: Power Tool A screw when the head is below the surface of the material it's fixing in to.


Categories: Power Tool Fine material shavings and dust created by drilling or sawing steel. The left over material when working with metals.



Categories: Gas Struts The rear, hinged hatched at the back of a vehicle that can be moved up or down when loading or unloading a vehicle. Gas struts are often used to lift or a tailgate. Also see:

Teeth (T)

Categories: Teeth When talking a blade, "T" will stand for Teeth. For example, 24T, 40T, etc. You might also see TPI which means "Teeth per Inch". As a rule, the higher the "T" or "TPI", the smoother the cut. Lower "T" or "TPI" will mean a rougher cut. Keep it simple:

      • 80T- cutting hardwoods
      • 40T - Cutting base boards
      • 24T- Cutting 2x4s

If you're working on building something like a shelf, where the edges don't matter as much, you can use a lower teeth rating to get the work done faster. If you want a better finish on something more delicate, use a blade with more teeth for a cleaner cut.

Telescoping jack

Categories: Garage A hydraulic jack with a piston that retracts and lifts in sections, allowing for a larger lifting range.


Categories: Generators A component that attaches to a conductor to facilitate a connection.


Categories: General, Gas Struts The helical structure that wraps around a section of a cylinder or cone used for fastening. Screws, nuts and bolts all have threads. Gas struts will have threaded ends that allow an end fixing to be attached. A bolt and gas strut is male threaded. A nut and end fixing is female threaded. ISO metric screw threads are used throughout the SGS product range.

Three phase

Categories: Generators, Air Compressors, SPX Three complete, separate sine waves spaced 120 electrical degrees apart. A three phase generator produces three-phase power output, making it ideal for powering heavy loads. Three phase generators tend to be more economical than single phase generators. Have a look at our  Generator Buying Guide for more help. A three-phase Tool such as an air compressor, will have a three-phase engine or motor and will require a three-phase power source. (see: Single Phase, Phase)

Titanium Coated Drill Bits

Categories: Power Tools High speed steel drill bits with a titanium-nitride protective coating, designed to help the drill stay cooler when in use. Particularly useful when drilling in metal. These accessory bits stay sharper longer and can be used for general drilling applications. (see: Bit)

Toe jack

Categories: Garage Similar to a standard bottle jack, however the toe-lift feature and swivelling pump handle socket of a toe jack make them ideal for machinery lifting and positioning


Categories: Power Tools A measurement of twisting force, often used to describe the power of a power tool. The higher the torque the more aggressively a tool will turn. High torque means the tool is turning a bit very hard.

TPI (Teeth Per Inch)

Categories: Power Tools A way of measuring the teeth on saw blades. Saw blades are rated by TPI and depending on what you need to cut, you may need to have a collection of wood blades, plastic blades, and metal blades with varying TPI's. (see: Teeth (T))

Transfer switch (TS)

Categories: Generators A device that switches a power load from the main utility power source to a standby source, such as a generator. Also see:

(see: Automatic Transfer Switch, Manual Transfer Switch)

Trolley jack

Categories: Garage A type of hydraulic vehicle jack that uses pistons to convert the downward force from a handle, to upward force of the ram.

Transmission jack

Categories: Garage A type of hydraulic jack specifically designed for removing and replacing a gearbox.

Tubular pin tumbler lock / tubular lock

Categories: Garage A component of many SGS tool chests, this locking mechanism uses 8 pins arranged in circular patten for a high level of storage security. Also see:

Two stage compressor

Categories: Compressor A compressor with a minimum of two cylinders. One cylinder will be smaller than the other, making it easy to identify the difference between the two types of compressors. Two-stage compressors are recommended where operating pressure exceeds 100 PSI / 7 bar or when tool usage is continuous. Normal operating pressure of a two-stage compressor is 175 PSI / 12 bar.

Two-stroke engine

Categories: Garden Also known as a two-cycle engine. A type of combustion engine that completes a full power cycle with two strokes (up and down) during one crankshaft revolution. Commonly used in petrol powered tools. The fuel requires two stroke oil to be mixed into the petrol.

Two-stroke oil

Categories: Garden Also know as a two-cycle oil. A special type of motor oil intended for the use in two-stroke engines. Different tools will require different mixes of two-stroke oil to petrol ratios, so you need to check in your instruction manual before you attempt to mix two-stroke oil with your fuel.

Tyre inflator

Categories: Compressor A simple air tool, powered by an air compressor, used for adding air to a vehicle tyre.


UK Mainland

Categories: General Orders over £100 ex VAT will automatically have free delivery applied when you add to basket if you live within the mainland, UK. Unfortunately this offer only extends to web orders with a delivery address in the UK mainland – N Ireland, Ireland, parts of Scotland, Highlands and Islands and International delivery addresses will have their exact carriage cost calculated during checkout. Also see:

Up-rating service

Categories: Gas struts SGS Engineering offer a unique service where an existing gas strut can have the force increased. This is useful for applications where additional weight has been added to an existing application, such as adding a bike rack or spoiler to a car boot. Also see:



Categories: Compressor, Hydraulics A device used to direct the flow, or stop the flow of air (air compressors) or liquids (hydraulics).

Variable Speed Trigger / Variable Speed Adjustment

Categories: Power Tools Allows the user full control of the speed of a power tool such as a drill/driver or saw. The harder you pull the trigger the more the tool will work. (see: Amp, Ohm)

Volt (V)

Categories: Generators A unit of measurement that denotes electromotive force. When this force is steadily applied to a conductor where the resistance is one ohm, it will produce one ampere.



Categories: General Ever product on the SGS website will have a warranty that covers manufacturing faults within a certain time period. SGS products will usually have a 2 year extended warranty, however tool chests have a 10 year warranty. You can see the individual warranty of each product on a product page under the technical specification. Also see:

Watt (W)

Categories: Generators A unit of measurement denoting electric power. In a direct current (DC): watts = volts x amperes. In an alternating current (AC): watts = effective amps x power factor x a constant dependent on the number of phases. 1000 watts (W)= 1 kilowatt (kW)

Welder generator

Categories: Generators Specially designed generators for welding applications. Also see:

Welfare generator

Categories: Generators Larger generators, typically use high end engines designed for accommodation or welfare units. Also see:


Categories: Generators The coils of a generator. Stator winding consists of a number of stator coils and interconnections. Rotor windings consist of all windings and connections in the rotor poles.

Wheel dollies

Categories: Garage A low profile cart with small caster wheels for moving heavy vehicles around a workshop or garage. They come in sets of twos or fours. Also see:

Wheel skates

Categories: Garage A low profile frame with small caster wheels for moving heavy vehicles around a workshop or garage. They come in sets of twos or fours. Also see:

Wheel chocks

Categories: Garage Wedges of sturdy material, such as rubber, plastic or metal, designed to stop a vehicle from moving when placed under the wheel They come in sets of two. Also see:

Whirl-away surface cleaner

Categories: Garden An accessory or a pressure washer that makes it easier to clean flat surfaces such as concrete floors, driveways, etc.