M2 | 1.3343 | SKH-51
M2 (1.3343 / HS6-5-2) is a tungsten-molybdenum high-speed steel offering excellent red hardness, wear resistance, and a good balance of toughness and cutting performance. It maintains hardness at elevated temperatures, making it suitable for a wide range of precision cutting tools.
Available Form
Round Bar
Custom Diameter & Length
Flat Bar
Custom Thickness, Width & Length
Square Bar
Custom Width & Length
Steel Plate
Custom Thickness, Width & Length
Steel Grade Comparison
| W-Nr | EN | AISI | JIS |
| 1.3343 | HS6-5-2 | M2 | SKH-51 |
Chemical Composition(wt%)
| C | Si | Mn | Cr | Mo | W | V |
| 0.78~0.88 | 0.20~0.40 | 0.20~0.40 | 3.75~4.50 | 4.50~5.50 | 5.50~6.75 | 1.60~2.20 |
Physical Properties
Density：8.12 g/cm³
Modulus of Elasticity: 217 GPa
Thermal Conductivity: 19.0 W/(m.K)
| Temperature | 20-100°C | 2-200°C | 2-300°C | 2-400°C |
| Coefficient of Thermal Expansion (×10-6 /K) | 10.7 | 11.7 | 11.9 | 12.4 |
Heat Treatment Process
Hardening: Pre-heat the steel, then heat to 1180~1220°C and quench in oil or air to cool.
Annealing: Heat to 820~870°C, hold well, then cool slowly inside the furnace.
Tempering: Heat uniformly at 540~600°C, hold for at least 1 hour, then cool in still air. Perform 2~3 times. Resulting hardness: 65~60 HRC.
Application Fields
Twist drills, thread cutters, hobs & dies for broaching / cold flow forming, cross recess dies for screws
Disclaimer: the information and data presented herein are typical values for reference and are not intended as warranties to readers.
