1144 Stressproof (Cold-Drawn Stress-Relieved) vs 1045 Steel
1144 Stressproof and 1045 are both medium-carbon steels for shafts, but 1144 is a cold-drawn, stress-relieved resulfurized grade engineered to deliver high strength with minimal distortion — no heat treatment needed. As listed, 1144 reaches ~690 MPa tensile / 620 MPa yield with good machinability (4.0), while 1045 sits at ~625 MPa / 530 MPa. Ready-to-use stress-free shafting versus standard medium-carbon bar.
The verdict
Choose 1144 Stressproof for shafts and machined parts that must stay dimensionally stable after machining without heat treatment — its cold-drawn, stress-relieved condition resists distortion and delivers high yield (~620 MPa). Choose 1045 for general medium-strength shafts and parts where standard bar and optional heat treatment fit the need at lower cost.
Side-by-side data
| Property | 1144 Stressproof (Cold-Drawn Stress-Relieved) | 1045 Steel |
|---|---|---|
| Category | Steel | Steel |
| Density (g/cm³) | 7.85 | 7.87 |
| Tensile strength (MPa) | 690 | 625 |
| Yield strength (MPa) | 620 | 530 |
| Elongation (%) | 10 | 12 |
| Hardness | 212 HB | 170 HB |
| Max service temp (°C) | 400 | 400 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 50 | 49 |
| Typically used for | Stress-free shafts without heat treat | Shafts & medium-strength components |
Which should you choose?
Choose 1144 Stressproof when…
- Machining shafts that must stay straight and stable (low residual stress)
- High strength is needed without heat treatment (~620 MPa yield)
- Distortion after machining must be minimized
- Better machinability than 1045 helps throughput (4.0 vs 3.0)
- Producing pins, studs, and spindles ready to use as-machined
- Stress-relieved, resulfurized free-machining medium-carbon bar suits the part
Choose 1045 Steel when…
- Standard medium-carbon shafting at lower cost (~1.1 vs 1.5 index)
- Parts will be flame- or induction-hardened for a wear surface
- Through-hardening by quench-and-temper is planned
- General shafts and components where stress-relief isn't critical
- Higher ductility is wanted (12% elongation vs 1144's 10%)
- A widely available, economical medium-carbon grade is preferred
Key differences that matter
- Both are ~0.45% carbon medium-carbon steels; 1144 adds sulfur for machinability and is cold-drawn + stress-relieved
- Strength: 1144 ~690 MPa tensile / 620 MPa yield vs 1045 ~625 MPa / 530 MPa — 1144 has ~17% higher yield as-supplied
- 1144's stress-relief gives low residual stress, so it machines without warping — its 'Stressproof' selling point
- Machinability: 1144 (4.0) beats 1045 (3.0) thanks to its resulfurized free-machining chemistry
- 1045 is preferred where flame/induction hardening or full quench-and-temper is needed for surface or bulk hardness
- Ductility: 1045 12% elongation vs 1144 10% — 1045 is slightly more forgiving
- Both are poor in corrosion (1.5/5); 1144 costs more (~1.5 vs ~1.1 index) for its processed condition
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Open the Material SelectorGet a Quote →Frequently asked questions
What is 1144 Stressproof steel?
1144 Stressproof is a medium-carbon (~0.45% C) resulfurized steel that's cold-drawn and stress-relieved to deliver high strength (~620 MPa yield) with very low residual stress. The processing means parts machine without warping or distorting — the reason it's branded 'Stressproof.' It's widely used for shafts and spindles that must stay straight after machining.
Is 1144 stronger than 1045?
In the as-supplied condition, yes. 1144 Stressproof offers about 690 MPa tensile and 620 MPa yield, versus roughly 625 MPa and 530 MPa for 1045 — about 17% more yield strength. 1144 also machines better and resists distortion. However, 1045 can be quench-and-tempered to reach higher strength when heat treatment is applied.
Why does 1144 resist distortion after machining?
1144 Stressproof is stress-relieved after cold drawing, which removes the internal residual stresses that normally cause bar stock to bend or warp when material is removed asymmetrically during machining. Because those stresses are relieved, parts stay straight and dimensionally stable — a major advantage for long shafts that would otherwise need straightening.
When should I choose 1045 over 1144?
Choose 1045 when you plan to heat-treat the part — flame or induction hardening for a wear surface, or full quench-and-temper for higher strength — or when you want a lower-cost, widely available medium-carbon bar and distortion isn't a concern. For ready-to-use, distortion-resistant shafting without heat treatment, 1144 is the better pick.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.