DIN 1.2510 / AISI O1 / JIS SKS3 Cold Work Tool Steel, its typical applications is making blanking, forming, and trim dies, gages, slitting cutters, punches, bolster dies, knock-out pins, thread roll dies, bending dies, plastic mold dies, shims, cams, machine ways, stamps, machine parts, jigs, cutter templates, swaging dies, etc.
Round: dia.10-500 mm
Flat: 6-120 x 40-1200 mm
Block: 80-400 x 100-1200 mm
EAF+(ESR) or EAF+LF+VD+(ESR), Hot rolled or Forged, Spheroidizing Annealed, Black surface or Machined surface, UT SEP1921 Class3 D/d
| AISI / SAE | DIN / W.Nr | JIS | GB |
| O1 | 1.2510 | SKS3 | 9CrWMn / CrWMn |
| Steel Grade | C | Si | Mn | P | S | Cr | W | V |
| 1.2510 | 0.90-1.05 | 0.15-0.35 | 1.00-1.20 | ≤ 0.030 | ≤ 0.030 | 0.50-0.70 | 0.50-0.70 | 0.05-0.15 |
| O1 | 0.85-1.00 | 0.10-0.50 | 1.00-1.40 | ≤ 0.030 | ≤ 0.030 | 0.40-0.70 | 0.40-0.60 | ≤ 0.30 |
| SKS3 | 0.90-1.00 | ≤ 0.35 | 0.90-1.20 | ≤ 0.030 | ≤ 0.030 | 0.50-1.00 | 0.50-1.00 | -- |
1. A kind of low-alloy cold work tool steel
2. With certain hardenability and wear resistance, homogenous and small particle carbides.
| Start Forging Temperature | Finish Forging Temperature | Cooling Method | |
| 1150 - 1200 °C | 1100 - 1150 °C | ≥920 °C | Slow cooling |
Annealing
The recommended annealing practice is to use controlled-atmosphere furnaces. If these are not available, pack-anneal in an inert material. For a quick annealing cycle to develop fair machining properties, heat slowly to 1375 to 1425°F. and cool slowly in the furnace. To develop the lowest hardness and best spheroidization for optimum machinability, heat slowly to 1450°F. and furnace cool at 20 degrees per hour to 900°F. The piece may then be removed from the furnace and cooled in air. Hardness after this cycle will be Brinell 202 max.
Stress relieving
When desirable to relieve the strains of machining, heat slowly to 1050°-1250°F, allow to equalize, and then cool in still air (Strain Relieving).The recommended annealing practice is to use controlled-atmosphere furnaces. If these are not available, pack-anneal in an inert material. For a quick annealing cycle to develop fair machining properties, heat slowly to 1375 to 1425°F. and cool slowly in the furnace. To develop the lowest hardness and best spheroidization for optimum machinability, heat slowly to 1450°F. and furnace cool at 20 degrees per hour to 900°F. The piece may then be removed from the furnace and cooled in air. Hardness after this cycle will be Brinell 202 max.
Hardening
After thorough prhe hardening furnace, operating from 1450°-1500°F, depending on the size of the part.Warm slightly before charging into the preheat furnace, which should be operating at about 1100°-1200°F.
Tempering
O1 is generally tempered in the range of 300°-600°F. Tempering temperatures and resulting Rockwell C hardness, based on a 1 inch round samples oil quenched from 1475°F and tempered for 2 hours, are as follows:
| Rockwell °C | |
| 300 | 65 |
| 350 | 63 |
| 400 | 62.5 |
| 450 | 61 |
| 500 | 60 |
| 600 | 57 |