Steel Feeds & Speeds Chart
Data for Low Carbon (1018), Medium Carbon (1045), and Alloy Steels (4140). Covers annealed and pre-hardened states.
Need Exact Numbers?
Steel hardness varies significantly. Use our calculator to adjust RPM and IPM based on exact Brinell or Rockwell hardness.
Low Carbon Steel (1018, A36)
Soft and gummy. Prone to built-up edge if not careful. Machines very easily.
| Tool Material | Operation | SFM Range | Chip Load (1/2" End Mill) |
|---|---|---|---|
| Coated Carbide | Roughing | 600 - 900 | 0.003" - 0.006" |
| Coated Carbide | Finishing | 800 - 1200 | 0.001" - 0.003" |
| HSS | General | 100 - 150 | 0.002" - 0.004" |
Alloy Steel (4140, 4340) - Annealed
The workhorse of engineering. Tough but machines cleanly with good chip control.
| Tool Material | Operation | SFM Range | Chip Load (1/2" End Mill) |
|---|---|---|---|
| Coated Carbide | Roughing | 400 - 650 | 0.0025" - 0.005" |
| Coated Carbide | Finishing | 600 - 800 | 0.001" - 0.002" |
| HSS | General | 70 - 100 | 0.002" - 0.003" |
Pre-Hardened / Tool Steel (P20, H13)
Hardness 30-45 HRC. Requires rigid setup and strict speed control to handle heat generation.
| Tool Material | Operation | SFM Range | Chip Load (1/2" End Mill) |
|---|---|---|---|
| Coated Carbide (AlTiN) | Roughing | 200 - 350 | 0.0015" - 0.003" |
| Coated Carbide (AlTiN) | Finishing | 300 - 450 | 0.0008" - 0.0015" |
Coating Guide: Steel
AlTiN / TiAlN
Color: Dark Grey / Violet
Best for Steel
High heat resistance (800°C+). Allows dry machining for chip evacuation.
TiCN (Titanium Carbonitride)
Color: Blue / Grey
Good Alternative
Lower friction than TiN. Good for stainless and harder steels.
Coolant vs. Dry Machining
For coated carbide in steel: Run DRY with Air Blast.
Thermal shock (rapid heating/cooling cycle) from liquid coolant can crack carbide inserts/end mills in steel. Use air blast to evacuate chips and let the heat leave with the chip.