Drill Bit Speed Guide: Correct RPM for Every Material (With Chart)

Drill speed — measured in RPM (revolutions per minute) — is one of the most misunderstood settings on a drill. Too fast and you burn the bit, work-harden the material, or produce rough holes. Too slow and you waste time. The right speed depends on the material, bit diameter, and bit type. Here is the complete guide.

Why Drill Speed Matters

Every material has an optimal cutting speed for its hardness and thermal properties. The relevant measure for drill bits is surface footage per minute (SFM) — how fast the cutting edge moves across the material. Since larger bits have a greater circumference, they reach higher surface speeds at the same RPM. This is why large bits always require lower RPM than small bits in the same material.

The practical consequence: a 1/2" bit in steel at 2,000 RPM will overheat and fail in minutes. The same bit at 500 RPM with cutting oil will last hundreds of holes. Getting the speed right is the single biggest factor in bit longevity.

Drill Bit Speed Chart by Material

Material	1/8" bit	1/4" bit	3/8" bit	1/2" bit	Cutting oil?
Softwood (pine, fir)	3,000	2,000	1,500	1,000	No
Hardwood (oak, maple)	2,500	1,500	1,000	750	No
Mild steel	3,000	1,500	1,000	750	Yes
Stainless steel	1,500	750	500	350	Yes
Cast iron	1,500	1,000	750	500	No (dry)
Aluminum	4,500	3,000	2,000	1,500	Yes (WD-40)
Brass / copper	3,000	2,000	1,500	1,000	Optional
Ceramic tile	600	400	300	200	Water
Porcelain tile	400	300	200	150	Water
Glass	400	300	200	150	Water
Concrete	Use hammer mode — RPM less important than impact rate				No
Plastic / PVC	3,000	2,000	1,500	1,000	No

RPM values are starting points for standard HSS or cobalt bits. Adjust based on heat buildup and chip color. These are not applicable to SDS hammer drilling in concrete.

How to Read Your Drill's Speed Settings

Most cordless drills have two speed ranges controlled by a gear selector (1 and 2):

• Speed 1 (Low): Higher torque, lower RPM — typically 0-500 RPM. Use for driving large fasteners, mixing, and drilling large holes in hard materials.
• Speed 2 (High): Lower torque, higher RPM — typically 0-2,000 RPM. Use for drilling small holes in wood and soft materials at full speed.

The trigger controls speed within each range — a light trigger pull gives low RPM within the selected gear range. For metal drilling, select Speed 1 and use moderate trigger pressure to stay in the 500-1,500 RPM range for most applications.

The Chip Color Test for Metal

When drilling steel, the color of the chips coming off the bit tells you if your speed is correct:

• Silver/bright chips: Speed is correct — material is cutting cleanly without excessive heat.
• Straw/gold colored chips: Getting warm — reduce speed or add more cutting oil.
• Blue/black chips: Too hot — reduce speed immediately. The material is work-hardening and the bit is overheating. This is the leading cause of premature bit failure in metal.

Concrete: Speed Doesn't Matter, Impact Does

Concrete drilling is completely different from metal and wood. In concrete, RPM is largely irrelevant — what matters is impact energy (joules) and BPM (blows per minute). The carbide tip chips away material through percussion, not cutting. Always use hammer mode; never try to drill concrete with rotation only regardless of RPM.

For concrete, match your drill to your bit: standard hammer drill for holes up to 1/2", SDS rotary hammer for larger holes and harder concrete. See our guide to hammer drill vs rotary hammer.

Tile and Glass: Slow and Wet

Ceramic tile, porcelain, and glass require very slow speeds and constant water cooling. High speed generates heat that causes thermal shock cracking in these brittle materials. Use a diamond-tipped bit, keep the RPM under 400, and keep the bit wet throughout the hole. A circle of plumber's putty around the hole location holds a small pool of water at the cutting point.

Related Guides

• Why Drill Bits Burn or Break — Speed and technique errors explained
• Cobalt vs Titanium Drill Bits — Which bit for metal work
• Best Masonry Drill Bits — Carbide bits for concrete and brick
• Hammer Drill vs Rotary Hammer — For concrete drilling work
• Drill Bit Selector — Instant bit recommendation for any material

Frequently Asked Questions

What RPM should I drill wood at?

For softwood (pine, fir, cedar) with standard twist or brad-point bits: 2,000-3,000 RPM for small bits (1/8"-1/4"), reducing to 1,000-1,500 RPM for larger bits (3/8"-1/2"). For hardwood (oak, maple, walnut): reduce these values by 20-30%. Higher speeds in wood are generally fine as long as you're not burning the wood — a scorched hole edge means too much speed or a dull bit.

What RPM should I drill steel at?

For mild steel with HSS or cobalt bits: 1,500-3,000 RPM for 1/8" bits, reducing to 500-750 RPM for 1/2" bits. Always use cutting oil on steel. Watch chip color — silver chips mean correct speed, blue chips mean too fast. For stainless steel, use the lower end of these ranges and never stop drilling mid-hole (the material work-hardens when stationary).

Why does my drill bit get hot so quickly?

The most common causes are: drilling too fast (RPM too high for bit size and material), not using cutting oil on metal, using a dull bit that generates friction instead of cutting, or drilling concrete without hammer mode. A hot bit in metal is losing its temper — the steel softens and the cutting edge rounds off rapidly. Slow down, add cutting oil, and let the bit cool between holes.

Does drill speed matter for concrete?

Not in the same way as metal and wood. Concrete drilling relies on the hammer mechanism chipping material rather than the bit rotating and cutting. RPM in hammer drilling primarily affects dust clearance from the flutes. What matters most for concrete is using hammer mode and having adequate impact energy — an SDS rotary hammer for holes above 1/2" diameter.