Drill Bits for Metal & Stainless Steel

Drilling steel comes down to two things: the bit material and the speed. Plain HSS handles mild steel and aluminum; stainless steel and hard metal call for cobalt. This page puts the metal-drilling bits we carry in one place, sorted by the job.

Twist drill bits for steel and stainless

M42 cobalt drill bits (8% cobalt) are the pick for stainless steel and hard metal, in metric 3–13mm singles or a 13-piece 1.5–6.5mm set. M35 cobalt jobber bits are sold individually from 0.5mm to 13mm, so you can replace only the size you wore out. For mild steel, aluminum and general shop work, the 13-piece titanium-coated HSS set covers the common metric sizes.

Sheet metal, spotting and larger holes

Step drill bits (4–12, 4–20 and 4–32mm) cut clean, round holes in sheet metal and electrical boxes, one size after another with the same bit. An HSS center drill spots the hole first so the twist bit doesn't wander. For 12–70mm holes in stainless sheet, use a TCT carbide hole saw; for 100–175mm, an M42 bi-metal hole saw.

Tips that make bits last

Run the drill slow, push firmly and use cutting oil on steel. If the chips turn blue, slow down. More detail in our guides to the best drill bits for metal and drilling stainless steel. Free shipping in 8–10 business days, or express for $4.99.