Brass Feeds & Speeds Chart
Quick-look reference data for brass milling across free-cutting, cartridge, naval, and high-strength brass grades. Best used as a shop-floor starting chart before you validate geometry, chip thickness, and grabbing risk in the calculator.
Need Exact Brass Milling Numbers?
Use this chart for a fast first pass. Then move to the copper-alloy calculator when cutter geometry, chip thickness, alloy family, or grab risk need a setup-specific answer.
What This Chart Covers Best
First-pass SFM and chip-load ranges for brass milling, slotting, and edge finishing where the main question is how freely the alloy cuts and how likely it is to grab.
Where It Needs Backup
Drilling, turning, and thin-wall work need feed-per-rev and breakthrough logic. Lead-free brass and high-strength brass also need calculator follow-through when geometry becomes the limiting factor.
Best Next Links
Branch to the copper-alloy calculator, turning calculator, or drilling calculator when the cut is no longer a simple milling reference.
Free-Cutting Brass (C360 / C385)
The king of machinability. C360 (also marketed as "Free-Cutting Brass") contains 3% lead, producing small, broken chips and allowing extreme cutting speeds. Used for fittings, valve bodies, and screw machine products.
| Operation | SFM (Carbide) | Chip Load (1/2" EM) | DOC (Roughing) |
|---|---|---|---|
| Roughing | 600 - 1000 | 0.004" - 0.008" | 1.0D - 1.5D |
| Finishing | 800 - 1200 | 0.001" - 0.003" | 0.02" - 0.05" |
| Drilling | 200 - 400 | 0.005" - 0.010"/rev | — |
Cartridge & Yellow Brass (C260 / C270)
Lead-free brass alloys required for plumbing (NSF/ANSI 61) and ammunition casings. Tougher than C360, produces longer chips, and has a greater tendency to grab. Reduce rake angle and increase feed.
| Operation | SFM (Carbide) | Chip Load (1/2" EM) | DOC (Roughing) |
|---|---|---|---|
| Roughing | 400 - 700 | 0.003" - 0.006" | 0.75D - 1.0D |
| Finishing | 600 - 900 | 0.001" - 0.002" | 0.01" - 0.03" |
Naval & High-Strength Brass (C464 / C675)
Tin-alloyed brass for saltwater applications (propellers, marine hardware). Significantly tougher than standard brass — treat closer to bronze. C675 (manganese bronze) is used in heavy-duty gears and bushings.
| Alloy | Operation | SFM (Carbide) | Chip Load (1/2" EM) |
|---|---|---|---|
| C464 Naval | Roughing | 300 - 500 | 0.003" - 0.005" |
| C464 Naval | Finishing | 450 - 700 | 0.001" - 0.002" |
| C675 Manganese Bronze | General | 200 - 400 | 0.002" - 0.004" |
The Grabbing Problem
Brass usually grabs because the geometry is wrong, not because the alloy is especially hard. This warning is mostly about milling and slotting, where a high-positive cutter can pull into the workpiece.
- Solution 1: Use 0° or negative rake geometry end mills specifically designed for brass/plastics.
- Solution 2: Use 2-flute uncoated polished end mills. The open flute space evacuates chips before they can re-cut.
- Solution 3: Maintain a positive, consistent feed rate. Never dwell or pause mid-cut. If the job is drilling or turning, switch to the dedicated calculator instead of guessing from a milling table.
Frequently Asked Questions
What SFM should I use for brass on a CNC mill?
For brass milling, this chart gives a first-pass window of 600–1000 SFM for C360 roughing with carbide and a lower range for C260 or naval brass. Use the copper-alloy calculator before release if geometry, cutter diameter, or chip load control will decide the outcome.
Why does my end mill grab when machining brass?
Standard end mills have high positive rake angles that pull the tool into soft brass. Use 0° or negative rake geometry, 2-flute uncoated tools, and maintain consistent feed — never dwell mid-cut.
Should I use coolant when machining brass?
Brass generates low heat compared to steel. Flood coolant is optional but helps chip evacuation. For C360, air blast is often sufficient. For lead-free alloys (C260), light mist or flood improves surface finish.
What coating should I use for brass end mills?
Uncoated polished carbide is usually the first choice for brass. ZrN can work well, especially in mixed non-ferrous shops. AlTiN is rarely the preferred starting point because brass usually benefits more from a sharper, lower-friction edge than from a heat-focused coating.
What is the difference between C360 and C260 brass?
C360 contains 3% lead for free-machining. C260 (cartridge brass) is lead-free, tougher, and produces longer chips. C360 allows 40–60% higher cutting speeds and much better chip evacuation.