BS970 817M40T/EN24T
817M40 /EN24T is a popular through hardening 1.1 /2% Nickel Chromium Molybdenum alloy steel which is supplied in the bright drawn, turned and hot rolled condition. It is also available in forged block form which can be cold sawn to size. 817M40T / EN24T is readily machineable in the hardened and Tempered “T” condition and offers good tensile, ductility and wear resistance properties, suitable for the manufacture of axles, gears, pins and studs.
817M40T / EN24T
| BS970: 1955 | BS970: 1991 | Description |
| EN24T | 817M40T | Bright/Black 1.1/2% nickel chromium molybdenum steel |
| Chemical Analysis | |
| Car | 0.36/0.44 |
| Si | 0.10/0.40 |
| Mang | 0.45/0.70 |
| Phos | 0.035 max |
| Sul | 0.040 max |
| Moly | 0.20/0.35 |
| Nick | 1.30/1.70 |
| Mechanical Properties | |
| Tensile Strength N/MM2 Min Rm | 850/1000 |
| Yield Stress NIMM2 Min Rm | 700 |
| Elongation A Min% on 5.65√SO | 9 |
| Izod Min | 54 |
| Kcv Min | - |
| Proof Stress 0.2% N/MM2 Min | 680 |
| Brinell Hardness | 248/302 |
| International Specification Comparison | |
| BS 970:1991 | 817M40T |
| BS 970: 1955 | EN24T |
| German Din | 34NiCrMo6 |
| French Afnor | 35NCD6 |
| Swedish SS | 2541 |
| American SAE | 4340 |
| European Steel No | 1.6582 |
| European Steel Name | 34CrNiMo6 |
| European Standard | EN10277-5 |
| Quick View System | |
| Machineability | 40 |
| Weldability | Pre / post heat precaution required |
| Hardenability | High strength up to 100mm dia |
| Selection Guide and Usage Examples | Popular direct hardening steel with good tensile. ductility, shock and wear resistance properties |
| Size Range Summary | ||
| Rounds | IMP | 3/8" -3" dia |
| MM | 10mm -310mm dia | |
