Drilling Metal: How to Drill Steel, Stainless & Hard Metals
Drilling through steel, stainless, or other hard metals doesn’t need to be difficult. With the right cobalt drill bit, correct speed, and a good lubricant, even a standard hand drill can produce clean, accurate holes. This guide walks you through the proven steps to drill metal safely and effectively—whether you’re a DIYer or a pro.
Need help with drill speeds or bit sizes? You’ll find clear technical resources and links throughout this guide.
Preparation: What You Need Before Drilling Metal
Before drilling any metal, a little preparation goes a long way. Run through this quick checklist:
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Identify the metal you’re drilling
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Select the correct drill bit for the job
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Choose a suitable power drill (preferably with variable speed)
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Apply a metal lubricant
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Wear proper safety protection
How to Drill Through Metal (The Basics)
1. Identify the metal you want to drill
This is without a doubt one of the most import thing to do before you can progress. However many people will not even consider that different metals react differently when being drilled. Most importantly the metal being drilled will determine:
- The best type of drill bit to be used
- The ideal cutting speed for your drill
- The amount of pressure to be applied
Anyone familiar with drilling stainless steel will confirm that if drilled at too high a speed and without adequate lubrication it will ‘work harden’ therefore making the drilling task infinitely more difficult.
For any novice confused by cutting speeds, pressure and having to identify metal a good rule of thumb would be to:
- Drill at a slow speed
- Use plenty of lubricant
- Drill for 10 seconds and stop, to allow the drill bit to cool for 20 seconds, lubricate and drill again for 10 seconds.
- Use light pressure.
- Use a good quality drill bit. If you are unsure of the metal you are drilling then a cobalt drill bit would be the best option.
Choosing the Right Drill Bit for Metal
2. Select appropriate drill bit type
With both the vast array of metals and the growing number of drill bit options it is understandable how choice of drill bit can be confusing. There are many different drill bit options for drilling metal and they include:
- Hi Molybdenum
- Cobalt
- Carbide tipped
- Solid carbide
- Diamond coated
- Diamond core
There will be a degree of overlap where the metal you wish to drill could be drilled by a number of drill bit options. Your choice may depend on budget and how often you will need to drill. Cobalt drill bits are often the choice for drilling metal due the large range of metals they will drill efficiently.
Wayne Winton of Tri-County Locksmiths in Colorado wrote an very informative piece for the publication Safe and Vault Technology in 2016 entitled ‘The ultimate guide to Drill bits‘ in which he highlights the abilities, pros and cons of different metal drill bits.
Drilling Metal with a Hand Drill
3. Choose a suitable power drill
For most non workshop applications a powered hand drill will be used. It is recommended that a power drill with adjustable speed be used as a slower speed is often required for drilling harder metals.
If buying a new power drill you should consider the size of the motor and whether you require a battery power supply or an electric cable power supply.
Most power drills now come with adjustable speed as a standard feature.If you are unsure of the speed to use it is generally advised to start with a slow speed and increase if you feel the drill bit is performing ok.
Lubrication When Drilling Metal
4. Choose a metal lubricant
Heat build up is inevitable when drilling metal. It is important to minimise heat build up as much a possible. A few methods can be used to keep heat build up to a minimum. One method is to drill in short bursts of perhaps 15 second intervals. Another obvious method, although too often overlooked, is to use a metal lubricant. Metal or drilling lubricants come in different forms ranging from oils to pastes. Both have advantages and disadvantages and choice often depends on the users preference.
If drilling harder metals on a regular basis it may be worth investing in a good quality drilling lubricant which has been tested and is known to contain extreme pressure additives.
CUT-IT is a metal cutting paste which contains extreme pressure additives and has been tested and certified by Sub Fluid Services.
Video shows CUT-IT metal drilling paste being used to assist in drilling of HARD 450
Safety Essentials
5. Wear suitable protection
In drilling metal it is absolutely vital to wear the appropriate level of protection for the job you are doing. At the very least you should wear suitable eye protection in form of safety glasses.
Then depending on the metal being drilled and the duration of the job you may need to use ear protection, gloves and a face mask.
FAQs – Drilling Metal
Q: What drill bit is best for drilling metal?
A: Cobalt drill bits (M35 grade) are the best all-round choice for drilling stainless steel, hardened steel, and other tough metals.
Q: How do you drill through metal with a hand drill?
A: Use a cobalt drill bit, set the drill to a slow speed, apply cutting paste, and drill in short bursts. Start with a small pilot hole, then step up to your final size.
Q: Do you need lubricant when drilling metal?
A: Yes. Cutting paste or oil reduces heat, prevents work-hardening, and extends drill bit life—especially when drilling stainless steel.
Q: Can you drill stainless steel with normal bits?
A: Standard HSS bits can struggle. A cobalt drill bit with cutting paste is recommended for stainless steel and hardened alloys.
Q: What size drill bit should you start with?
A: For most jobs, pilot with 3–4 mm (≈1/8″), then increase step by step to your required size for a cleaner finish.
Drilling metal : Further info
How to Drill Metal on WiKi HOW How to drill into steel like a pro Ask the Builder
12 tips for drilling holes in metal Family Handyman How to drill in metal SKIL
