In order to successfully complete a range of different tasks as part of home DIY projects, car repairs and other bits of work, impact wrenches prove incredibly useful. In some cases they are an essential tool and it’s important to choose the right one for the job.
If you’re asking the question "what are impact wrenches for?" then here at SGS Engineering we have the answer. We’ve put together this handy post explaining what impact wrenches are, what they’re used for and the best ones to buy. So if you’re considering adding to your toolbox, an impact wrench could be a great choice.
So what’s the difference between the different types of impact wrenches and which is the right one for you? This chart gives a quick break down of all the tools you'll see in this piece;
|Brand||Name||Power Source||Use||Max Torque||Max Speed|
|SAT103||Air||DIY||340 Nm||7000 rpm|
|SAT101||Air||Professional||880 Nm||7000 rpm|
|BIW180M||Battery||DIY||265 Nm||3000 rpm|
|R18IW3-0||Battery||DIY||400 Nm||2900 rpm|
|M18BIW38-0||Battery||Professional||210 Nm||2450 rpm|
|M18FHIWF12-0||Battery||Professional||1898 Nm||1700 rpm|
|M12FIW38-0||Battery||Professional||339 Nm||2700 rpm|
|M18BRAIW-0||Battery||Professional||7 Nm||2250 rpm|
|KWT-002-06||Battery||Professional||430 Nm||2750 rpm|
In many ways an impact wrench is what people use when no other wrench is up to the task. They are socket wrench power tools which deliver a high torque output without much effort required by the user. Impact wrenches supply additional force in cases where more power is required for both assembling and disassembling tasks, such as loosening and tightening particular screws.
They may look like drills but rather than supplying constant rotational power at a high speed impact wrenches deliver high torque at a low speed through a hammering action. Air or electricity is used to power motors which applies a quick twisting motion to the recalcitrant lug nut in short bursts. These rapid bursts bring about movement for loosening or tightening.
What are Impact Wrenches For?
Having an electric impact wrench in your garage and/or car is a great place to keep it for changing vehicle tyres, especially as you won’t have an air compressor out on the road. Their main use is for bolting and unbolting screws easily, so impact wrenches can be used for putting up garden decking, removing wheels and more.
Impact wrenches are widely used in many industries, such as automotive repair, heavy equipment maintenance, product assembly, major construction projects, and any other instance where a high torque output is needed. Impact wrenches get their immense torque from a hammering mechanism in the tool that delivers strong concussive blows extremely quickly. When loosening a lug nut you'll notice the socket attached to the impact wrench moving slowly as the lug nut is loosened and then quickly when it's loose. Be cautious when tightening lug nuts using an impact as it's easy to over torque them—which can stretch or even strip the threads.
Which Impact Wrench Do I Buy?
The impact wrench you buy will depend on what your main use for it will be. Air powered options are favoured by professional tradesmen and mechanics as their power supply isn't likely to run out half way through a job. Air powered, pneumatic impact wrenches are generally more powerful and lighter to use, with most professionals favouring them for home construction and mechanical work. However, electric impact wrenches provide more than enough power for average DIY tasks, these tend to be the favourite choice as users prefer something a bit more mobile for home use and may not have access to an air compressor.
Air Powered DIY
1/2” Air Impact Wrench With Rubber Grip - 340 Nm
- Sturdy rubber grip
- Four torque settings
- Free speed of 7000 RPM
- Product Weight 2.18kg
- Max Torque - 340 Nm
- Operating Pressure - 90 PSI
- Required Air CFM - 8 SCFM
Air Powered Professional
1/2" Heavy duty Air Impact Wrench – 880Nm
- Sturdy positive rubber grip
- Free speed of 7000 RPM
- Max Torque 880 Nm
- Product Weight 2.8kg
- Operating Pressure 90 PSI
- Required Air CFM 6.5 SCFM
This Air Impact Wrench is an essential tool for all DIY and professional mechanics, helps to remove stubborn and rusty nuts and bolts. With powerful output of 880 Nm, this tool will be able to rapidly do the job on even the most ambitious of projects. With 3 forward speeds and a reverse action, stay in control of your work piece with this impressive air tool. Designed to be robust, durable and safe, SGS air tools make a dependable addition to any workshop. With rubber textured handles for superior control and special twin hammer mechanism, you can’t go far wrong with this impact driver.
Battery Powered DIY
Ryobi ONE+ BIW180M 18V, 265Nm Impact Wrench
- Drive Size 1/2 Inch
- Max Torque 265 Nm
- Voltage 18V
- Keyless 1/2˝ Drive
- Impact rate (ipm)3500
- No load speed gear 1 (rpm)0-3,000
Ryobi ONE+ R18IW3-0 18V, 400Nm Cordless 3-Speed Heavy Duty Impact Wrench
- ½” square drive locking pin
- Max Torque 400 Nm
- Voltage 18V
- ¼” hex adapter
- No load speed 2900 rpm
This feature rich 18V lithium-ion impact wrench utilises a powerful motor to deliver up to 400Nm of torque, enabling you to tackle even the toughest wheel nuts and driving applications. Fitted with a ½” square drive locking pin for easy socket fitment and coming complete with ¼” adapted, this impact wrench from Ryobi is the perfect driving tool. The innovative impact mechanism allows huge amounts of torque with little feedback through the GripZone handle.
Battery Powered Professional
Milwaukee M18BIW38-0 Compact 3/8" Impact Wrench
- Drive Size 3/8 Inch
- Voltage 18V
- Product Weight 1.5kg
- Impact rate : 0 - 3,350 ipm
- Max. torque : 210 Nm
- No load speed : 0 - 2,450 rpm
Kielder KWT-002-06 18V 1/2" 430Nm Professional Heavy-Duty Brushless Impact Wrench
- Max Torque: 430Nm
- Drive: 1/2” Square
- Tool Length: 152mm
- Weight (with battery): 1.7kg
- Speed: 0-2750rpm
- Impact Rate: 0-3250ipm
Powered by a smooth digital brushless motor and fuelled by high-tech Samsung Li-Ion batteries (sold separately), the Kielder KWT-002 Impact Wrench delivers high torque performance in a compact size. Well balanced and comfortable to operate, even in those tight / awkward areas. Makes easy work of assembly or disassembly tasks around the garage and workshop.
Milwaukee M18FHIWF12-0 Gen2 18V 1/2" 1898Nm Impact Wrench
- Drive Size 1/2 Inch
- No load speed (rpm) 0 - 425 / 0 - 1700
- Impact rate (ipm) 0 - 450 / 0 - 2300
- Tool reception 1.2. square
- Max. fastening torque (Nm) 1354
- Nut busting torque (Nm) 1898
Milwaukee M12FIW38-0 Fuel 3/8" Impact Wrench
- 4-Mode Drive Control
- Mode 1 - 0-1200 RPM and 0-1100 IPM
- Mode 2 - 0-1800 RPM and 0-2100 IPM
- Mode 3 - 0-2700 RPM and 0-3200 IPM
- 339 Nm of Maximum torque
- 3 Year Warranty
The Milwaukee M12FIW38-0 offers precise and easy use thanks to its reduced size of 125mm. 1/2˝ Anvil with friction ring gives user quick and easy access to socket changes. Up to 339 Nm of Maximum torque. Advanced system of cordless power tool electronics. Provides optimized performance and overload protection using total system communication between tool, battery and charger
Milwaukee M18BRAIW-0 18v Right Angle Impact Wrench
- Length: 308mm
- Head Diameter: 53mm
- Anvil Size: 3/8" Square
- Anvil Type: Friction Ring
- Drive Size: 9 pt /5mm
- Max speed 2250 rpm
- Max torque 7Nm
The Milwaukee M18BRAIW Cordless Right Angle Impact Wrench offers users maximum access, and ultimate speed & control over their hard to reach fastening applications. Its 43mm head profile fits where pistol-grip impact tools cannot, and its extended paddle switch allows trademen to operate their tool from multiple grip points. This tool measures 307 mm in length making it ideal for working within confined spaces.
Still not sure which impact wrench to choose?
As well as designing our own range of air tools, SGS engineering works closely with various suppliers to ensure we only stock the very best impact wrenches. Our in house experts are always on hand for buying advice and to provide bespoke care, regardless of the application. Whether you’re just starting out on a new hobby or you have complicated commercial requirements, we’ve got the in-house experts to help.