1144 Steel
A resulfurized medium-carbon steel with high manganese
Typical values for the temper in the title
1144 contains about 0.44% carbon, high manganese and sulfur. The sulfur breaks the chip, so it machines much better than 1045. Manganese and carbon give it high strength.
In the version known as Stressproof it is heavily cold drawn and stress relieved, reaching a very high yield strength without hardening, with good dimensional stability in machining. It is used for shafts and precise parts that need strength.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 703 MPa | |
| Yield strength Rp0.2 | 586 MPa | |
| Elongation A | 16% | |
| Hardness | 212 HB | |
| Modulus of elasticity E | 200 GPa | |
| Density ρ | 7.85 g/cm³ | |
| Machinability | 83% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| C carbon | 0.40–0.48 | strength |
| Mn manganese | 1.35–1.65 | strength and MnS inclusions |
| S sulfur | 0.24–0.33 | chip breaker |
| P phosphorus | max 0.040 | |
| Fe iron | balance |
Ranges per SAE J403. Equivalents in other standards are close in composition, not identical.
Conditions and heat treatment
1144 is usually chosen precisely to avoid heat treatment: the strength comes from cold work.
| Condition | Properties | When to choose it |
|---|---|---|
| Cold drawn and stress relieved (Stressproof) | high yield without hardening | shafts and precise parts |
| Induction hardened | hard surface | wear surfaces |
Applications
- Precision shafts and bars
- High-strength machine parts
- Piston rods
- Automatic lathe parts
- Pump shafts
Fabrication
Machining
Much better than 1045 thanks to the sulfur.
Dimensional stability
In the Stressproof version residual stresses are low, and the part warps less in machining.
Welding
Not recommended: sulfur causes cracking.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| 1045 | 570–700 / 310–450 MPa | Medium | more weldable, but machines less well · material page |
| 4140 | 655–1000 / 415–835 MPa | Medium — Preheat 150C | alloy steel, for high strength by hardening · material page |
| 12L14 | 540 / 415 MPa | Poor — Pb causes Hot Crack | machines faster, but is weak · material page |
Common mistakes
Welding 1144
Sulfur causes cracking.
Replacing 1045 with 1144 in a shock-loaded part
Sulfur lowers transverse toughness.
Heat treating Stressproof without recalculating
Heat treatment removes the strength gained by cold work.
Equivalents, standards and supply
| EN | 44SMn28 (close) |
|---|---|
| JIS | SUM43 |
| Standards | ASTM A29 / SAE J1392 |
| Forms | rod (Cold Drawn) |
| Producers | Nucor · TimkenSteel · US Steel |
Learn more
Values are typical and for comparison only, and depend strongly on condition and diameter. For design, rely on the standard and on the mill certificate. Sources: SAE J403 and J404, ASTM A29, A322 and A519 (composition), producer data sheets, and the METAL HUB materials database.
Updated: October 31, 2026