Tool Steel M4

Aging Procedure

Not applicable to this alloy.

Annealing Procedure

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

Applications

Used for cutting tools of all types for machining operations.

Cold Workability

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

Forgeability

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

Formability

Forming in the annealed condition is satisfactory by conventional methods.

Hardening Procedure

See "Heat Treatment" and "Tempering".

Heat Treatability

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

Hot Workability

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

Machinability

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

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.

Principle 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.

Tempering Procedure

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

Weldability

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