OHNS
Grade Introduction:
OHNS steel is a general-purpose tool steel that is typically used in applications where alloy steels cannot provide sufficient hardness, strength, and wear resistance. Chemical composition of OHNS is Carbon 0.94%, Manganese 1.2%, Silicon 0.30%, Chromium 0.50% and Vanadium 0.15%.
Grade Application:
• Blanking and stamping dies,
• Punches,
• Rotary shear blades,
• Thread cutting tools,
• Milling cutters,
• Reamers,
• Measuring tools,
• Gauging tools,
• Woodworking tools,
• Broaches,
• Chasers.
Equivalent grades:
| STANDARDS | 100MnCrW4 | O1 | DIN 2510 | AISI O1 | AFNOR 90MWCV5 | JIS SKS3 |
Chemical composition:
The following table shows the chemical composition of OHNS steel:
| Element | C | Si | Mn | P | S | Cr | W |
| Content (%) | 0.85-1.00 | 0.15-0.35 | 1.00-1.20 | 0.03 Max | 0.03 Max | 0.50-0.70 | 0.50-0.70 |
Hardness:
Max. 230
Heat treatment:
| Soft Annealing °C | 750-780 |
| Cooling | Furnace |
| Hardness HB | Max. 230 |
| Stress-relief Annealing °C | Approx. 650 |
| Hardening °C | 780-820 |
| Quenching | Air, Oil, Salt Bath 180-220 °C |
| Hardness after quenching HRC | 65 |
Hardening:
O1 steels should be heated uniformly to 780-820°C (1436-1508°F) until completely heated through. If needed, the steels can be preheated at 300-500°C (572-932°F). About 30 min/per 25 mm of the ruling section is to be provided and then the steels should be immediately quenched in oil.