Drill Bit Chooser
Metal drilling

Which drill bit should you use for metal?

Mild steel, aluminum and other non-ferrous alloys do not share the same cutting conditions. If you do not know the material, identify it before selecting a tool or setting speed.

Quick answer

For ordinary mild steel, a ground HSS-G twist bit is a practical starting point. For common non-ferrous metals, a suitable HSS-G bit may also work—but the exact alloy changes the cutting approach. Stainless and hardened steel deserve separate decisions.

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Interactive selector

Find a bit for your setup

Answer only the questions that change the selection. If the combination is not documented, the tool will say so.

Anchor / safety details (important for wall drilling)

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This does not verify workpiece condition, bit stock length, chuck capacity, structural loads or exact cutting speed. Follow the chosen manufacturer’s specification and use appropriate eye, hearing, workpiece and dust protection.

What changes the bit choice?

First identify the metal

Mild steel, aluminum and other non-ferrous alloys do not share the same cutting conditions. If you do not know the material, identify it before selecting a tool or setting speed.

A twist bit, not a masonry bit

Bosch’s ground HSS-G twist-bit guidance covers steel and various non-ferrous materials. Drill in rotary mode with the hammer function off. Select the appropriate diameter, usable length and shank fit for the actual drill.

Speed and lubricant depend on the job

A bit family is not a complete drilling procedure. The selected manufacturer’s instructions, metal grade, bit diameter and workpiece setup determine feed, speed, cooling and lubrication.

Common mistakes to avoid

  • Using hammer/percussion mode on metal.
  • Treating hardened steel as interchangeable with mild steel.
  • Quoting one RPM number for every bit size or alloy.

Frequently asked questions

Can I use the same bit for stainless steel?

Do not assume so. A cobalt-alloyed HSS bit specifically rated for stainless steel is a documented choice. Use the dedicated stainless-steel selector.

Do I need a cobalt bit for ordinary steel?

Not necessarily. An appropriately specified ground HSS twist drill is a reasonable ordinary-steel category; the exact workpiece and required life determine any upgrade.

Need a different material? Browse all ten material guides. Interested in wall fixings? Read our anchor-size warning and workflow.