Knowing which drill bit you need means the difference between doing the job right and doing the job twice. There are a myriad of different types of drill bits out there, so it’s easy to get overwhelmed with the choice.
Before you start shopping for your newest drill bit, it’s important to know what job it is that you’re doing. Is it a drill bit for drilling into stone, or wood?
Here at SGS, we’ve put together a guide to make sure that buying and using drill bits is easy. Take a look.
Drill Bit Features and Useful Terms
While there are many different types of drill bit, there are some universal features that make a drill bit a drill bit and not something else.
Point - The cone shaped, pointed end which does the cutting. This section consists of a spur and cutting lip.
Spur - The spur sits at the dead centre of the point. This helps to get the drill into position.
Cutting Lip - The cutting lip scrapes away the wood. This is the feature that generally varies from bit to bit.
Flutes - Starting from the cutting lip, a flute or channel spirals its way up the body of the drill bit where it ends with the shank. The flutes help the cutting lip remove the displaced material.
Shank - The portion of the drill bit that is clamped into a spindle (or straight into a drills chuck, with a straight shank drill bit).
Choosing the Right Bit for Your Application
Multi Purpose Drill Bits: Everyday Use
This most common and widely available of all drill bits. Used for general purpose, this set is perfect for drilling in to metal, wood and stone but in rotary mode only. For diameters of 12 mm and more, the drills are supplied with a hexagonal shank eliminating the risk of slippage in the chuck.
Auger Drill Bits: Neat Holes in Wood
Similar to multi purpose drill bits, except that they have a more pronounced central point or spur, auger drill bits are easy to locate and keep on course. They are used solely for drilling wood, and they produce holes with very neat edges. This means that this type of bit is favoured over others when the appearance is important.
Spade Drill Bits: Large, Rough Holes in Wood
Spade Drill Bits are designed for drilling large holes quickly and roughly in wood. They can cause splintering around the entry and exit of a hole, however. Available in large diameters, they are ideal for cutting holes in timber posts for cables, wires, pipes and ropes. You can find a seven piece spade drill bit set here, offering you a range of different sizes, from 10mm up to 32mm in a sturdy moulded plastic case, ideal for caballing and home DIY
Masonry Bits: Drilling Masonry, Concrete & Stone
If you’re drilling into brick, light concrete, limestone, natural or artificial stone, then masonry drill bits are necessary. The cutting tip is usually made out of tungsten carbide on a steel shaft. The most suitable type of drill bit for these applications is the Milwaukee 4932352333 5 Piece Drill Bit Set. The diamond ground percussion carbide tips gives two cutting edges whilst vibrations are damped and impact energy is transferred directly to the drill tip.
Self Feed Drill Bit: Large, Rough Holes in Heavy Duty Wood
The Milwaukee 49220130 Self Feed Drill Bit Set is ideal for the professional plumber and electrician who needs to make large, rough holes in wood designed for woodcutting, installing pipes, conduits and repetitive drilling for large holes.
The self feed bit drills into materials without pressure which provides cleaner and faster holes. The drill bits have reduced run out, coated with a rust inhibitor and the hex shank provides a secure gripping surface for the drill chuck. The drill bits are built to perform and last and can be resharpened to keep them cutting like new.
HSS Drill Bits: Drilling Metal and Hardwood
For metal and harder woods, you need High Speed Steel, or HSS. They are hard, and resistant to heat, much more so than high carbon steel, which means that they can be used at high speeds. These Milwaukee high speed steel rollforged metal drill bits boast an oxide coating enabling quick swarf removal. They're suitable for drilling in to steel, cast iron, alloyed and non-alloyed material up to 800 N/mm².
Selecting Screw Driving Bits
As well as drilling holes in a variety of materials, most drills will also have a driving function for fixing various screws. Selecting the right screw driving bit is relatively straight forward, but we’ve put together a couple of simple steps so you can grab the right bit for any given application.
Step 1: Find the Shape of the Screw
More specifically, look at the screw’s drive, or shape pressed into the head of the screw. The most common screw types you’ll come across are Phillips, Pozi Drive, Slotted and Hex drive heads, however you might find screws with Square, Torx and Security Torx+ drive heads too.
Use the table bellow to work out what screw you’re looking at and what type of bit you need.
Step 2: Find the Size of the Screw
After you have established the shape of your screw head and picked the appropriate shaped bit drive, you need to select the correct size bit. Picking the perfect sized bit will ensure it doesn’t slip when you’re inserting a bit or driving the screw.
The best way of choosing the right size bit is trial and error. Bit kits normally come with the most common sizes for everyday tasks. For example, with Phillips PH1, PH2 and PH3 bits on hand, you’ll almost definitely be able to tackle any driving tasks around the home and garden.
It’s easy to find the one that fits: if it moves in the recess when you turn the screw by hand, try a larger bit! Beware: a bit that fits very snugly in the screwhead is likely to strip the head.
Choosing the Best Driver Bit Set for You
Now you know which bit to choose for any given application, selecting an appropriate bit set is simple. The more ambitious your projects are, the bigger the set you should purchase. You can always add more specialist sets later on, but a good combination bit and driver set can we you through the vast majority of household tasks.
Ryobi RAK16FP 16 Piece Screwdriver Bits Set for Flat Pack Furniture
This 16 piece accessory set from Ryobi includes various screwdriver bits including Hex, Phillips, Pozi Drive and Slot heads, making it perfect for all those jobs around the home and flat pack furniture. Included is a magnetic 60mm bit holder for easy access to your bits, making bit changes simple and easy and tough moulded carry case.
Milwaukee 4932430907 56 pc Shockwave Drill/Screwdriver Bit Set
Not only is this kit ideal for heavy duty impact applications, but it also delivers a full system solution for all your drilling and fastening needs. The custom engineered steel makes the Shockwave bits more resistant to shock from impacting. The precision milled tip provides the best fit in the screw head, reducing cam out and stripping, resulting in outstanding lifetime, up to 30X longer life.