Tool Steel M7

Aging Procedure

Not applicable to this alloy.

Annealing Procedure

Anneal at 1550 to 1600 F and slow cool in furnace at less than 40 F per hour.

Applications

M7 is widely used for cutting tools in machining operations.

Cold Workability

In the annealed condition M7 may be cold worked by conventional methods.

Forgeability

Forging may be done in the range of 2100 F to 1700 F. Do not forge below 1700 F.

Formability

M7 in the annealed condition may be formed by conventional means.

Hardening Procedure

See "Heat Treatment" and "Tempering".

Heat Treatability

Preheat at 1450 F and then heat rapidly to 2200 F. Hold parts at 2200 F for 2 to 5 minutes and then salt bath, oil or air quench.

Hot Workability

See "Forging".

Machinability

Machinability is medium, rating about 60% that of the W group water hardening low alloy tool steels at 100% for comparison.

Principle Design Features

M7 is one of the High Speed Tool Steels in the molybdenum alloy family, with tungsten, chromium and vanadium for strengthening. It has good hardenability and is very wear resistant.

Tempering Procedure

Temper at 1000 F to 1100 F for Rockwell C of 66 to 61. A double temper at the same temperature for one hour each time is preferred.

Weldability

This is a complex alloy but is weldable. Consult the supplier for procedures and details.