It is a new plastic mould steel which is designed by refering to the disadvantages and advantages ofS-136 and 1.2316.
| Standard | Chemical Composition | C | Mn | Si | Cr | P | S | Mo | Ni |
| GB1220 | % | 0.30/0.40 | ≤ 1.00 | ≤ 1.00 | 16.0/17.5 | ≤ 0.025 | ≤ 0.020 | 0.80/1.30 | 0.60/1.00 |
Features:
1) pure and precision mirror polishing
2) strong corrosion resistance and its pitting corrosion goes beyond S-136 and 1.2316
3) convinient heat treatment
4) quenched and tempered steel after pre-handed, its dimension become more stable
5) Its resistance is as good as S-136 and 1.2316, and easy to repair welding