Flat Drill Bits
Flat drill bits – also called spade bits – are perfect for fast, rough drilling through wood. With wide blades and sharp tips, they bore clean holes in joists, studs and board without clogging.
Who Uses Flat Drill Bits?
Popular on site where speed matters more than finish, especially for:
- Electricians – Bore holes for cable runs through studwork.
- Plumbers – Drill pipe access through battens, frames and panels.
- Carpenters – Pre-cut holes for fixings and conduit mounts in timber.
- Multi-traders – Knock out holes for sockets, switches, or fittings.
Flat Drill Bits Are Great for Jobs Such As:
- Drilling through studs for electrical cable
- Cutting out timber for pipe runs
- Rough boring in MDF or chipboard panels
- Mounting wall fixings behind cladding
- Speedy holes where the finish isn’t critical
How to Choose the Right Flat Bit
Flat bits come in multiple widths and tip styles – here’s what to keep in mind:
1. Width
Match the width to the cable or pipe size – 16mm to 32mm are common for first fix.
2. Shank Type
Standard hex shank fits most cordless drills. Impact-rated versions are ideal for site use.
3. Tip Design
Spur tips help centre the bit and start clean. Some designs have side cutters for smoother holes in dense timber.
Best Accessories for Flat Bits
Get faster, straighter holes and longer bit life with these accessories:
1. Bit Extensions
Drill deeper through multiple layers of wood or studwork.
2. Sharpening Stones
Keep blade edges sharp and effective job after job.
3. Depth Stops
Prevent overdrilling or bursting out the back face of your timber.
Frequently Asked Questions
Are flat bits good for clean holes?
No – they’re designed for speed, not finish. Use auger or brad point bits if appearance matters.
Can I use flat bits in a cordless drill?
Yes – they work great in 18V drills. Choose impact-rated versions for combi drills or impact drivers.
What size flat bit do I need?
Typical sizes for first fix are 16mm, 20mm, 25mm and 32mm – depending on the cable or pipe being routed.
What’s the difference between flat and auger bits?
Auger bits drill deeper and cleaner, but slower. Flat bits are faster and cheaper for rough work in wood.
Can I use flat bits in MDF?
Yes – but go slow and back off at the end to avoid blowout. Keep bits sharp to avoid tearing.
