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Carbon		1.25 - 1.4
Chromium		3.75 - 4.75
Iron		Balance
Manganese		0.15 - 0.4
Molybdenum		4.25 - 5.5
Phosphorus		0.03 max
Silicon		0.2 - 0.45
Sulphur		0.03 max
Tungsten		5.25 - 6.5
Vanadium		3.75 - 4.5

Principal Design Features		M4 is another in the Molybdenum High Speed Tool Steels. It has a relatively high 1.3% carbon content for high hardness and excellent wear resistance.

Applications		Used for cutting tools of all types for machining operations.

Machinability		Machinability is relatively low, rating 40% that of the water hardening (W group) tool steels which are relatively easy to machine.

Forming		Forming in the annealed condition is satisfactory by conventional methods.

Welding		This is an alloy steel and may be welded. Consult the supplier for details.

Heat Treatment		Preheat at 1450 F and then heat rapidly to 2225 F for 3 to 5 minutes followed by oil, salt bath or air quench.

Forging		Forge at 2050 F down to 1700 F. Do not attempt to continue forging below 1700 F.

Hot Working		M4 may be hot forged. No data in regard to hot working . Consult the alloy supplier for temperatures.

Cold Working		Cold working may be accomplished by conventional methods with the alloy in the annealed condition.

Annealing		Anneal at 1625 F and slow furnace cool at 40 F per hour or less.

Aging		Not applicable to this alloy.

Tempering		Temper at 1050 F for a Rockwell C hardness of 62 to 66.

Hardening		See "Heat Treatment" and "Tempering".

Other Comments		M4 is one of the best of the Molybdenum High Speed Tool Steels in regard to wear resistance. However it has low toughness.

Physical Data : [top]

Density (lb / cu. in.)	0.295
Specific Gravity	8.16
Melting Point (Deg F)	2600
Modulus of Elasticity Tension	29

MSO currently has no data available for this grade.