Direct Answer: A drill bit makes a round hole, and the right choice depends on the material you are drilling and the machine you are using. Choose HSS for general work, cobalt for tougher metals, carbide for hard materials, and a masonry or wood bit for brick or timber.
The wrong bit wastes time, ruins material and wears out fast.
This short guide covers the main types of drill bit, the materials they are made from and a few tips for better holes. It is written for workshops, fabricators and contractors in the UAE.
Al Rizq is an authorised distributor of Supercut cutting tools and supplies Supercut drill bits in Dubai and across the UAE.
What Are the Main Types of Drill Bit?
Each type of bit is made for a specific job, so match the bit to the material first.
Twist Drill Bits
Twist drill bits are the standard bit for general drilling in metal, plastic and wood. They come in many sizes and lengths. Choose the diameter for your hole, and remember that a shorter bit is more rigid and less likely to flex.
Spot (Centre) Drills
Spot drills are short, rigid bits that start a hole accurately. The drill that follows then does not wander off the mark.
Masonry Bits
Masonry bits are carbide-tipped bits for brick, block and concrete. They are used with a hammer or rotary-hammer drill where suitable.
Wood Bits
Spade, auger and Forstner bits are made for wood. Spade bits make quick, rough holes, auger bits suit deep holes, and Forstner bits cut clean, flat-bottomed holes.
Next, the material a bit is made from decides how well it handles heat and wear.
Which Drill Bit Material Should You Choose: HSS, Cobalt or Carbide?
Three materials cover most metal drilling, and each suits a different job.
High-Speed Steel (HSS)
HSS is a general-purpose, economical choice for drilling steel, aluminium, plastics and wood.
Cobalt
Cobalt bits are HSS with added cobalt. They are more heat resistant than plain HSS and are used for tougher materials such as stainless steel.
Carbide
Carbide is very hard and holds an edge longer, which suits production work and hard materials. It is more brittle, so it needs a rigid machine and set-up.
Many bits are also coated to reduce friction and wear. Check the product specification for the coating, and match the bit material to the job first.
Which bit for which material? Ask us
Tell us the material, hole size and machine, and we will help you choose a suitable bit.
Which Drill Bit Should You Use for Each Material?
Use this table as a starting point, then check the manufacturer’s recommendation for your exact job.
| Material | Suitable bit |
|---|---|
| Mild steel, aluminium, plastic | HSS twist drill |
| Stainless steel and tougher alloys | Cobalt or carbide twist drill |
| Brick, block, concrete | Carbide-tipped masonry bit |
| Wood | Spade, auger or Forstner bit, depending on the hole |
On the specification, check three things: the diameter and length, the bit material and the shank type your machine can hold.
For a step-by-step method, read our 6-step framework for choosing drill bits by material. You can also see our guide on solid carbide drills replacing HSS jobber drills.
How to Drill Cleaner, More Accurate Holes
A few habits improve hole quality and extend the life of every bit.
- Start accurate holes with a spot drill, and drill a smaller pilot hole before a large one.
- Use a lower speed for harder materials and larger bits, and use cutting fluid when drilling metal.
- Clamp the work, wear eye protection and clear chips as you drill.
- Use peck drilling for deep holes, retracting the bit to clear chips and bring in cutting fluid.
- Replace or resharpen dull bits, because a dull bit overheats and leaves rough or oversized holes.
Once you know which bit you need, the next step is buying it from a reliable supplier.
Supercut Drill Bits and Cutting Tools From Al Rizq
Al Rizq is an authorised distributor of Supercut cutting tools and supplies Supercut drill bits, alongside a wider range of cutting tools.
Describe the material, hole size and machine, and we will help you pick a bit and check availability.
For the machines that run them, see our drilling machines.
Describe the job, pick the bit
Tell us the material, hole size and machine, or browse the Supercut range first.
Frequently Asked Questions
Which drill bit sets are worth the investment for contractors?
Choose a set that matches the materials you drill most often. An HSS set is the economical choice for general metal work. Add cobalt or carbide bits only if you regularly drill tougher materials.
What is the difference between HSS and cobalt drill bits?
Cobalt bits are HSS with added cobalt, which makes them more heat resistant. They suit tougher materials such as stainless steel, while plain HSS suits general work.
What drill bit should I use for steel?
Use an HSS twist drill for mild steel. For stainless steel and tougher alloys, choose a cobalt or carbide twist drill, and use cutting fluid.
Can I use a wood bit on metal or masonry?
No. Spade, auger and Forstner bits are made for wood. Use a twist drill for metal and a carbide-tipped masonry bit for brick, block and concrete.
Is Al Rizq a Supercut distributor in the UAE?
Yes. Al Rizq is an authorised distributor of Supercut cutting tools and supplies Supercut drill bits in Dubai and across the UAE.
What is a spot drill used for?
A spot drill starts a hole in the right place so the drill that follows does not wander. Choose a spot drill whose point angle matches or exceeds that of the drill bit.