How to Drill Through Metal – 10 Expert Tips for Better Results
Drilling through metal can feel intimidating, especially if you’ve snapped a few bits in the past. Whether you’re working with stainless steel, aluminium, or mild steel, using the right technique makes all the difference.
Below are 10 expert tips to help you drill cleanly, safely, and efficiently — plus answers to the most common questions and mistakes people make when drilling metal.
1. Identify the Metal You’re Drilling
Metals vary in hardness. Aluminium is soft and forgiving. Stainless steel and Hardox are much harder and require tougher tools. Knowing your metal helps determine the right drill bit and speed.
2. Use the Correct Drill Bit
Standard HSS bits may work for soft metals, but for harder types like stainless or spring steel, you’ll need a cobalt drill bit. These are designed for hard materials and offer better durability and heat resistance.
Browse cobalt drill bits for metal »
3. Choose a Variable Speed Drill
High-speed drilling creates heat and shortens bit life. A variable speed drill lets you control the RPM, allowing you to start slowly and build up as needed.
4. Secure the Metal with a Clamp
Always clamp your metal to a stable surface. This prevents the workpiece from spinning, slipping, or catching — which can be dangerous and result in inaccurate holes.
5. Wear Safety Glasses
Drilling metal can release long spirals and sharp shards at high speed. Protect your eyes with proper safety glasses or a face shield every time.
6. Match the Drilling Speed to the Metal
Different metals require different speeds. A drill speed and feed chart can guide you on RPMs based on bit size and material hardness.
As a general rule: the harder the metal, the slower the speed.
7. Mark the Drilling Point with a Centre Punch
Before drilling, use a centre punch or even a nail to create a small dent where the bit should start. This helps the bit stay in place and prevents it from skating across the surface.
8. Use a Metal Cutting Paste or Lubricant
Friction causes heat, which can destroy bits and harden the metal. Always apply lubricant or cutting paste before and during drilling. It reduces heat, makes drilling smoother, and extends bit life.
Use our premium CUT-IT metal cutting paste »
9. Apply Steady, Moderate Pressure
Let the bit do the cutting. Forcing it increases friction and leads to overheating. Use consistent, moderate pressure — firm enough to bite, but not so hard that you’re pushing aggressively.
10. Drill in Short Bursts
Continuous drilling can overheat both bit and metal. Drill in short intervals, pausing every few seconds to cool the bit and apply more lubricant if needed.
Common Mistakes to Avoid When Drilling Metal
❌ Using the Wrong Drill Bit
Standard HSS bits will quickly wear out or fail on hard metals. Use cobalt for better results on stainless and tough steel.
❌ Drilling Too Fast
High RPMs generate extreme heat and dull bits. Slow and steady is far more effective.
❌ No Lubrication
Friction without lubrication causes excessive heat, smoke, and bit wear. Always use cutting paste.
❌ Forgetting to Centre Punch
Starting without a punched hole can cause the bit to skid, damaging the surface and wasting time.
❌ Letting the Metal Move
Unclamped material can spin, making the drill bind or even throw the workpiece. Always secure it.
FAQs – How to Drill Through Metal
What drill bit is best for metal?
Cobalt drill bits are best for most metals, especially stainless steel, hard steel, and other tough alloys. They’re stronger and more heat-resistant than standard HSS bits.
Do I need lubricant when drilling metal?
Yes. Lubricants or cutting paste reduce friction, keep the bit cool, and improve cutting efficiency. They also extend the life of the bit significantly.
How do I stop a drill bit from slipping on metal?
Use a centre punch to mark the exact spot before drilling. This creates a small divot that keeps the bit steady and prevents it from skating.
Can I drill stainless steel with normal bits?
No — stainless steel is too hard for regular HSS bits. Use a cobalt drill bit with cutting paste, slow speed, and short bursts for best results.
Need the Right Tools?
Whether you’re drilling steel, aluminium, or stainless, having the right gear makes it easier and safer. Get started with our top-selling tools below: