Stainless Steel Feeds & Speeds Chart
Quick-look reference data for 303, 304, 316, 17-4PH, and 400 series stainless milling. Best used as a starting chart before you validate work-hardening risk, coolant strategy, and cutter engagement in the calculator.
Need Exact Stainless Milling Numbers?
Use this chart for a fast first pass. Then move to the stainless calculator when tool diameter, coating, coolant, and work-hardening risk need a setup-specific answer.
What This Chart Covers Best
First-pass SFM and chip-load ranges for stainless milling, especially when you need a quick comparison between 303, 304, 316, 17-4PH, and 400 series behavior.
Where It Needs Backup
Turning, drilling, tapping, and high-pressure-coolant workflows need operation-specific feed-per-rev logic. Age-hardened 17-4 and duplex jobs also need closer condition checks before release.
Best Next Links
Branch to the stainless calculator, turning calculator, or drilling calculator when the cut moves beyond a quick milling reference.
300 Series (303, 304, 316)
The most common stainless steels. 303 is free-machining (sulfur added). 304/316 are gummy and work-harden instantly if you rub.
| Material | Operation | SFM (Coated Carbide) | Chip Load (1/2" End Mill) |
|---|---|---|---|
| 303 Stainless | Roughing | 400 - 600 | 0.003" - 0.006" |
| 303 Stainless | Finishing | 600 - 800 | 0.001" - 0.002" |
| 304 / 316 | Roughing | 250 - 450 | 0.0025" - 0.005" |
| 304 / 316 | Finishing | 350 - 550 | 0.001" - 0.002" |
17-4 PH & 400 Series
Magnetic stainless steels. 17-4 PH is widely used in aerospace. Harder than 300 series but often machines cleaner (less gummy).
| Condition | Operation | SFM (Coated Carbide) | Chip Load (1/2" End Mill) |
|---|---|---|---|
| H900 (Age Hardened) | Roughing | 150 - 300 | 0.002" - 0.004" |
| H900 (Age Hardened) | Finishing | 250 - 400 | 0.001" - 0.002" |
| 416 / 420 (Free Machining) | General | 350 - 600 | 0.003" - 0.006" |
Coating Selection for Stainless
AlTiN / TiAlN
Color: Dark Grey / Violet
Standard Choice
Excellent heat resistance. Forms aluminum oxide protective layer at high temps.
TiN (Titanium Nitride)
Color: Gold
Acceptable
Okay for general use, but lower heat resistance than AlTiN.
Uncoated
Color: Silver
NOT RECOMMENDED
Stainless generates too much heat. Carbide will degrade rapidly without thermal barrier.
Critical Rule: Don't Let It Rub!
Stainless steel (especially 304/316) work hardens instantly. If your tool dwells, rubs, or takes too light of a cut (less than 0.001"), the surface will become harder than the tool itself.
Solution: Maintain a positive chip load in milling, keep the tool moving, and do not guess drilling or turning feeds from a milling table. If the job is not primarily milling, move to the dedicated calculator so feed-per-rev and entry conditions are not being approximated.
Frequently Asked Questions
What SFM should I use for 304/316 stainless steel?
For stainless milling, this chart gives a first-pass window of 250–450 SFM for coated-carbide roughing in 304/316, with 303 usually running higher. Use the stainless calculator before release if cutter size, coolant, or engagement materially change the cut.
Why does stainless steel work harden?
Austenitic stainless naturally work hardens when deformed. If the tool rubs or takes too light a cut, the surface becomes harder than the tool itself.
What is the best coating for machining stainless steel?
AlTiN/TiAlN is standard. TiN is acceptable. Uncoated is NOT recommended due to extreme heat.
What is the difference between 303 and 304 stainless for machining?
303 has sulfur added (free-machining), allowing 40–60% higher SFM. 304/316 are gummy and work-harden if the tool dwells.
What chip load should I use for stainless steel?
For a 1/2-inch end mill in 304/316, 0.0025–0.005 IPT is a practical chart range for roughing and 0.001–0.002 IPT for finishing. Those numbers are for milling only; use the turning or drilling calculator when the job changes feed units or entry conditions.