O1 Tool Steel (100MnCrW4) | 
                        
|---|
| O1 toolsteel is a medium alloyed cold work steel with good hardening capacity, high wear resistances, dimensionally stable during heat treatment. 
 Applications: Cutting and punching tools, shear knives, thread rolling tools, measuring instruments.  
 | 
| Colour Code | Stocked Sizes | |
Blue/Green![]()  | 
Rounds | 
20 mm - 222 mm Dia | 
| Condition of Delivery | 
||
| Soft annealed to max. 230 HB | ||
| Related Specifications | 
|
| Germany | DIN 1.2510 | 
| USA | AISI O1 | 
| Chemical Composition | |||||||||||
| % | |||||||||||
| Carbon | 0.95 | ||||||||||
| Manganese | 1.10 | ||||||||||
| Chromium | 0.60 | ||||||||||
| Tungsten | 0.60 | ||||||||||
| Vanadium | 0.10 | ||||||||||
| Physical Properties | |||||||||||
| Thermal expansion coefficient | ![]()  | 
||||||||||
| Thermal conductivity | |||||||||||
| Heat Treatment | |||||||||||
| Soft Annealing | |||||||||||
| Temperature | 740 - 770oC | ||||||||||
| Cooling | furnace | ||||||||||
| Hardness | max 230 HB | ||||||||||
| Stress Relief Annealing | |||||||||||
| Temperature | 600 - 650oC | ||||||||||
| Cooling | furnace | ||||||||||
| Hardening | |||||||||||
| Temperature | 790 - 820oC | ||||||||||
| Cooling | oil or hot bath 180 - 220oC  | 
||||||||||
| Hardness | see tempering diagram | ||||||||||
| Thermal Cycle Diagram | |||||||||||
![]()  | 
|||||||||||
| Continuous Cooling Transformation Diagram (CCT) | |||||||||||
![]()  | 
|||||||||||
| Tempering Diagram | |||||||||||
![]()  | 
|||||||||||