Reference Chart
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.
Material chart
Stainless Steel Feeds and Speeds Reference
Starting stainless milling ranges for 303, 304, 316, 17-4PH, and 400-series grades before work-hardening validation.
| Grade / condition | Starting SFM | Chip load window | Release note |
|---|---|---|---|
| 303 stainless roughing | 400 - 600 SFM | 0.003 - 0.006 IPT on 1/2 in end mill | Free-machining grade supports higher starts. |
| 304 / 316 roughing | 250 - 450 SFM | 0.0025 - 0.005 IPT | Keep feed positive to avoid work hardening. |
| 304 / 316 finishing | 350 - 550 SFM | 0.001 - 0.002 IPT | Confirm finish and heat behavior. |
| 17-4PH H900 roughing | 150 - 300 SFM | 0.002 - 0.004 IPT | Condition and hardness drive the window. |
| 416 / 420 general milling | 350 - 600 SFM | 0.003 - 0.006 IPT | Free-machining martensitic grades cut cleaner. |
| Coolant boundary | Operation dependent | Do not rub | Coolant concentration and chip evacuation affect work hardening. |
Download / export next steps
Download stainless reference PDF
Export the summarized stainless grade, SFM, work-hardening, coolant, and tool-life reference.
Validate Stainless Milling Setup Values
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.
Reference handoff
Stainless table handoff
Use this chart for stainless reference ranges, then route work-hardening and operation-specific release through calculators.
Best starting point
Reference values for stainless milling across 300 series, PH, and duplex families.
Branch when
Turning, drilling, and chip-load release need calculator validation.
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.