Steel Speeds & Feeds Calculator 2026
Optimized parameters for carbon steel, alloy steel, and heat-treated grades. From 1018 mild steel to 4340 HT - complete coverage.
Calculate Steel Parameters
Steel Machining Guide
Steel is the most commonly machined material in manufacturing. From low-carbon mild steel to high-strength alloy steels, understanding the differences between grades is essential for optimal machining.
Steel Categories
🔵 Low Carbon Steel (1010-1025)
Carbon: 0.05-0.25%
Easy to machine, soft and ductile. Excellent for welding and forming. Can be case hardened. May cause built-up edge at low speeds.
- • 1018: Most common, general purpose
- • 1020: Slightly harder than 1018
- • A36: Structural steel plate/bar
🟡 Medium Carbon Steel (1040-1060)
Carbon: 0.30-0.60%
Good balance of strength and machinability. Can be through-hardened. Commonly used for shafts, gears, and structural parts.
- • 1045: Most popular medium carbon
- • Used for high-strength parts
- • Can be induction hardened
🟣 Alloy Steel (4130, 4140, 4340)
Alloying: Cr, Mo, Ni, V
Higher strength and hardness than plain carbon steel. Excellent for high-stress applications. More difficult to machine when hardened.
- • 4130: Chromoly, good weldability
- • 4140: Common general-use alloy
- • 4340: High-strength for critical parts
🟢 Free Machining Steel
Additives: S, Pb, Bi, Se
Specifically designed for high-speed production. Superior chip breaking, lower tool wear, better surface finish. May have reduced weldability and mechanical properties.
- • 12L14: Leaded, 170% machinability
- • 1144: Stressproof®, 83%
- • Ideal for screw machine parts
Cutting Speed Reference Table
| Grade | Machinability | Milling (m/min) | Turning (m/min) | Drilling (m/min) |
|---|---|---|---|---|
| 12L14 | 170% | 200-400 | 280-540 | 70-150 |
| 1018 | 70% | 150-300 | 200-380 | 50-110 |
| 1045 | 55% | 100-200 | 130-260 | 35-75 |
| 4140 | 66% | 100-200 | 130-260 | 35-75 |
| 4140 HT (28-32 HRC) | 45% | 60-130 | 80-170 | 20-50 |
| 4340 HT (35-40 HRC) | 30% | 40-95 | 55-120 | 15-38 |
* Speeds for coated carbide tools (TiAlN). Reduce by 60-75% for HSS.
Tool Selection Guide
Soft Steel (<200 HB)
- ✓ Carbide with TiCN/TiAlN coating
- ✓ Positive rake geometry
- ✓ Larger chip loads acceptable
- ✓ Flood coolant recommended
Medium Hard (200-320 HB)
- ✓ Coated carbide essential
- ✓ Neutral rake geometry
- ✓ Moderate chip loads
- ✓ Ensure good chip evacuation
Hardened (>45 HRC)
- ✓ CBN or ceramic inserts
- ✓ Negative rake geometry
- ✓ Light DOC (0.1-0.3mm)
- ✓ Often dry machined
Frequently Asked Questions
For milling with coated carbide: 150-300 m/min (490-985 SFM). For turning: 200-380 m/min (650-1250 SFM). Mild steel is easy to machine - you can be quite aggressive. 12L14 free machining steel can go even faster at 280-540 m/min for turning.