1038 vs 1040
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
1038
Carbon Steel
1038 is a medium carbon steel widely used in North American cold drawn and hot rolled bar for shafts and bolts. It sits between 1035 and 1045 and is often specified where 1045 hardenability is not needed.
Standards: DIN C35/C40 (near) · AISI 1038 · JIS S35C/S40C (near) · GB 38 (near)
1040
Carbon Steel
1040 is a medium carbon steel for moderately stressed shafts, bolts and gears. It is the plain-carbon predecessor of 5140/40Cr in many cost-sensitive designs, with similar carbon but no chromium hardenability boost.
Standards: DIN 1.0511 (C40) · AISI 1040 · JIS S40C · GB 40
Chemical composition compared (%)
| Element | 1038 | 1040 |
|---|---|---|
| C | 0.35–0.42 | 0.37–0.44 |
| Mn | 0.60–0.90 | 0.60–0.90 |
| P | ≤0.040 | ≤0.040 |
| S | ≤0.050 | ≤0.050 |
Properties compared
| Property | 1038 | 1040 |
|---|---|---|
| Tensile strength | 540–640 MPa (normalized, typ.) | 570–660 MPa (normalized, typ.) |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: 1038 · 1040. Substitution decisions for certified parts stay with the design authority.