OHNS
OHNS (Oil Hardening Non-Shrinking) steel is a high-carbon tool steel known for its excellent hardness, wear resistance, and dimensional stability during heat treatment. It is commonly used in applications such as dies, punches, and cutting tools due to its ability to withstand high-stress conditions without compromising its integrity.
Tool Steels
Tool and Die Steel Includes Cold Work Steel, Hot Work Steel, Plastic Mould Steel, High Speed Steel. These tool materials adhere to great quality demands of steel like temper, strength, toughness, resistance to tempering, hardening capacity, dimensional stability etc. The range of Tool Steel in our store includes products from renowned manufacturers
Main characteristics and applications
Medium alloyed cold work steel with good hardening capacity, high wear resistance, dimensionally stable during heat treatment.
Its applications are small tools for cutting and punching, shear knives, thread rolling tools, measuring tools, wood working tools.
Critical points
Ac1 740 °C
Ac3 770 °C
Ms 215 °C
Production technology
EAF – LF – VD – Forging – Heat treatment +A
US specification
In according to standard EN10228-3 Class 4 and standard SEP 1921 Class E/e
Delivery condition
WW.NR. 1.2510 is delivered in annealed condition, with hardness max 230 HB (21 HRC).
Comparable standards
| DIN | W.Nr | AFNOR | AISI/ASTM | JIS |
|---|---|---|---|---|
| 100MnCrW4 | 1.2510 | 95MnWCr5 | O-1 | SKS3 |
Chemical composition (typical; in weight %)
| C | Si | Mn | P (Max) | S (Max) | Cr | W | V |
|---|---|---|---|---|---|---|---|
| 0.90-1.05 | 0.15-0.35 | 1.00-1.20 | 0.035 | 0.035 | 0.50-0.70 | 0.50-0.70 | 0.05-0.15 |
Physical properties
| Property | 20°C | 100°C | 500°C |
|---|---|---|---|
| Thermal expansion coefficient (10⁻⁶/K) | 11.4 | 11.7 | 12.7 |
| Thermal conductivity (W/m·K) | 29.9 | 30.1 | 31.2 |
| Young's modulus (kN/mm²) | 212 | 209 | 175 |
Heat treatment
| Treatment | Temperature (°C) | Holding Time | Cooling | Comments |
|---|---|---|---|---|
| Annealing | 700 – 720 | Min. 2 min/mm | Furnace to 600°C, then air | — |
| Stress relieving | 600 – 650 | Min. 2 min/mm | Air or furnace | — |
| Hardening | 790 – 820 | Min. 1 min/mm | Oil or pressure gas (vacuum) | — |
Type: Oil hardening cold work tool steel
Density: ~7.85 g/cm³
Hardness (annealed): ≤ 230 HB
Hardness (hardened & tempered): 58-64 HRC
Key Characteristics: Good wear resistance, excellent dimensional stability during hardening, good machinability
Typical Applications: Punches, dies, cutting tools, gauges, mandrels, forming tools
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Precision Weight Calculator for Steel Sections