1.0721 (10S20) vs 1215
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.
1.0721 (10S20)
Carbon Steel
10S20 (1.0721) is a case-hardening free-cutting steel under EN 10087: moderate sulfur (0.15–0.25%) balances machinability against the ability to carburize small parts that need a wear-resistant case — a combination plain free-cutting grades cannot offer.
Standards: DIN 1.0721 (10S20)
1215
Carbon Steel
1215 is a rephosphorized and resulfurized free-cutting steel with very low carbon, built purely for machining speed. It is one of the fastest-cutting bar steels available and a staple of high-volume screw machining.
Standards: AISI 1215 · JIS SUM25 (near) · GB Y12 (near)
Chemical composition compared (%)
| Element | 1.0721 (10S20) | 1215 |
|---|---|---|
| C | 0.07–0.13 | ≤0.09 |
| Si | ≤0.40 | — |
| Mn | 0.70–1.10 | 0.75–1.05 |
| P | ≤0.06 | 0.04–0.09 |
| S | 0.15–0.25 | 0.26–0.35 |
Properties compared
| Property | 1.0721 (10S20) | 1215 |
|---|---|---|
| Case hardness (carburized) | 55–62 HRC (typ.) | — |
| Tensile strength | 360–480 MPa (delivery-condition dependent) | 380–460 MPa (hot rolled, typ.) |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
| Machinability | — | ≈135% of 1212 (typ. rating) |
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: 1.0721 (10S20) · 1215. Substitution decisions for certified parts stay with the design authority.