M42 | 1.3247 | SKH59
M42 is a molybdenum series high-speed steel alloy with an additional 8 or 10 percent cobalt. It is widely used in metal manufacturing industries because of its superior red hardness as compared to more conventional high-speed steels. This allows for shorter cycle times in production environments due to its higher cutting speeds and from the increase in time between tool changes. M42 is also less prone to chipping when used for interrupted cuts and costs less when compared to those same tools made of carbide.
Description
Chemical Composition
| Standard | Grade | C | Si | Mn | Cr | P | S | Mo | V | W | Co |
| ASTM | M42 | 1.05-1.15 | 0.15-0.65 | 0.15-0.40 | 3.50-4.25 | ≤0.03 | ≤0.03 | 9.00-10.00 | 0.95-1.35 | 1.15-1.85 | 7.75-8.75 |
| DIN | 1.3247 | 1.05-1.15 | ≤0.70 | 3.50-4.50 | 9.00-10.00 | 0.90-1.30 | 1.20-1.90 | 7.50-8.50 | |||
| JIS | SKH59 | 1.05-1.15 | ≤0.70 | ≤0.40 | 3.50-4.50 | ≤0.03 | ≤0.03 | 9.00-10.00 | 0.90-1.30 | 1.20-1.90 | 7.50-8.50 |
Supply Range
Surface Finish: Black, Peeled, Machined/Turned or as per given requirements.
Forged Round Bar: 20mm - 650mm (Dia)
Rolled Bars: 12mm - 360mm (Dia)
Forged flats: 30-400mm(T)*500-1200mm(W)
Rolled flats: 10-360mm(T)*30-1020mm(W)
Other sizes of O1 material or as per customer’s requirements
Heat Treatment
Annealing
AISI M42 high speed steel is heated at 871°C (1599°F) and then cooled slowly in a furnace.
Stress Relieving
To relieve stresses created by extensive machining or tooling with complex geometries. Heat in a neutral atmosphere for 1 to 2 hours after reaching a temperature of 1110 to 1200°F (600 to 650°C), followed by slow cooling in the furnace.
Hardening
AISI M42 high speed steel is preheated to 871°C (1599°F), soaked and finally heated to 1204°C (2199°F).
Tempering
Tempering M42 tool steel at 560°C / 1040°F or higher 3 times for at least 1 hour at full temperature is recommended.
Application
AISI M42 tool steel is a high-speed steel suitable for cutting tools such as, twist drills, broaches, taps, milling, cutters, saws, reamers etc. In terms of performance, HSS grade M42 is a steel to be used in conditions where the demand for hot hardness is of great importance i.e. where high performance is essential.
Typically employed to machine the super alloys and exotic, AISI HSS M42 tool steel is employed in drills, hobs, taps, end mills, milling cutters, form and gear cutters, broaches and chasers.
