Main Characteristics and Applications
Heavy-duty milling cutters of all kinds, highly stressed twist drills and taps, profile knives, machining of high-strength materials, broaches.
Comparable standards
| DIN | W.Nr | AFNOR | AISI/ASIM | JIS |
|---|---|---|---|---|
| S 6-5-2-5 | 1.3243 | Z85WDKCV06-05-05-04-02 | M-35 | SKH55 |
Chemical composition (typical; in weight %)
| C | Si (max) | Mn (max) | P (max) | S (max) | Co | Cr | Mo | V | W |
|---|---|---|---|---|---|---|---|---|---|
| 0.87-0.95 | <0.45 | <0.40 | 0.03 | 0.03 | 4.50-5.00 | 3.80-4.50 | 4.70-5.20 | 1.70-2.10 | 5.90-6.70 |
Steel properties
The cobalt content in this high-performance high-speed steel results in high red hardness and tempering resistance. As a consequence, this grade is particularly suitable for conditions involving thermal stresses and discontinuous cutting. Under the name Rapidur 3245, AISI M 35 + S and material number 1.3245, this steel grade is supplied with a higher sulphur content (S = 0.10 %).
Heat treatment
| TREATMENT | TEMPERATURE | COOLING | HARDNESS | |||
|---|---|---|---|---|---|---|
| Annealing | Heat to 770 – 860 °C | Furnace | max. 269 | |||
| Stress-relief annealing °C | Heat to 630 – 650 °C | Furnace | - | |||
| 1st pre-heating °C | 2nd and 3rd pre-heating °C | Hardening1 °C | Quenching | Tempering °C | Quenching | |
| up to approx. 400 in an air-circulating furnace | a) 850 | 1190 – 1230 | a) Saltbath, 550 °C | at least twice 530 – 560 | 64 – 67 | |
| - | b) 850 and 1050 | - | b) Oil | - | - | |
| - | - | - | c) Air | - | - | |
For cold-forming tools with a complex geometry, a hardening temperature at the lower end of the quoted range is recommended. The stated hardening temperatures apply to saltbath hardening only. For vacuum hardening, we suggest a reduction of 10 °C to 30 °C.