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Brass Speeds and Feeds

Guide · Updated October 28, 2026

Free-machining brass like C360 is the easiest common metal to cut: it runs fast, makes small chips and finishes well. The catch is that it grabs. Tools with positive rake can pull themselves into the work, which matters most when drilling and boring.

Brass parts are often precise

Fittings and bushings need tight sizes. Check your mic against gage blocks. The free Gage Block Calculator builds the stack.

Step by step

Know the alloy: C360 free-machining brass cuts freely; C260 cartridge brass and bronzes are gummier and slower.
Pick a starting SFM: C360: about 300 SFM with HSS and 600–1,000 SFM with carbide. Slow down 30–50% for gummier alloys.
Use zero rake: Stone a small flat on drill lips and use neutral-rake tools so they do not grab.
Set the feed: Brass likes a steady, moderate feed; too light and it work-hardens slightly and rubs.
Coolant or dry: C360 can run dry; a light oil or soluble coolant helps finish and tool life.
Hold it securely: Thin brass parts can be pulled out of the vise by a grabbing tool.
Deburr: Brass burrs are small but sharp; break edges before measuring.

Worked example

Turning a 1.000 in C360 bar with an HSS tool at 300 SFM: RPM = 3.82 × 300 ÷ 1.000 = 1,146 RPM. At 0.005 in/rev the carriage moves 5.7 IPM. With carbide at 800 SFM it runs about 3,056 RPM if the lathe can reach it. For a 1/4 in drill at 250 SFM: 3.82 × 250 ÷ 0.250 = 3,820 RPM.

Why brass grabs

A positive rake angle wants to dig in, and brass is soft and free-cutting enough that the tool pulls itself forward, taking up backlash. That can snap drills or yank a part. Dubbing the cutting edge to zero rake stops it.

Getting a fine finish

Use a sharp tool with a small nose radius, a moderate feed and plenty of speed. A lighter final pass of 0.005 in usually gives a bright finish.

Tips

Compare: aluminum and cast iron speeds and feeds.
Drilling: drilling speeds and feeds.
Turning: turning speeds and feeds.

FAQ

What SFM for brass with HSS?

About 300 SFM for free-machining C360.

Why does my drill grab in brass?

Its positive rake pulls it in; stone the lips to zero rake.

Do I need coolant for brass?

Not for C360; a light oil helps finish.

Is bronze the same as brass?

No; most bronzes are tougher and need slower speeds.

Can I use aluminum tools on brass?

Sharp tools work, but high positive rake can grab; neutral rake is safer.

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