M4 is an extremely versatile high-speed steel with its extremely high carbon and vanadium contents for exceptional abrasion-resistance. It is well suited for premium cutting tools of all types, particularly those used for machining abrasive alloys, castings and heat-treated materials. The high carbon content enables M4 steel to be hardened in excess of 65HRC. However, the high hardness and high vanadium carbide content make it more difficult to grind after heat treatment compared to M2 and other high-speed steels.
Other Known Names: HS 6-5-4, E M4, SKH 54, Stark.
Griggs Steel Color Code:Green
Form Tools, Punches, Broach Inserts, Mills, Taps, Header Tooling.
Density
0.288 lb/in3 (7972 kg/m3)
Specific Gravity
7.97
Modulus Of Elasticity
30 x 106 psi (207 GPa)
Machinability
35-40% of a 1% carbon steel
| Maximum | Typical | ||||||
|---|---|---|---|---|---|---|---|
| Carbon | Chromium | Tungsten | Molybdenum | Vanadium | Cobalt | Annealed | Tempered |
| C | Cr | W | Mo | V | Co | Hb | HrC |
| 1.3 | 4.25 | 5.85 | 4.75 | 4.1 | - | 255 | 65 |
| Annealing | Preheat | Austenitizing | Quench | Tempering |
|---|---|---|---|---|
| Temp | Temp | Temp | Medium | Temp |
| °F | °F | °F | °F | |
| 1550/1600 | 1500/1550 | 2175/2225 | Salt/Oil/Atm | 1025/1050 |
Heat rapidly from the preheat.
Annealing must be performed after hot working and before re-hardening
Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1550-1600°F (843-871°C), and hold at temperature for 1 hour per inch (25.4 mm) of thickness, 2 hours minimum. Then cool slowly with the furnace at a rate not exceeding 50°F per hour (28°C per hour) to 1000°F (538°C). Continue cooling to ambient temperature in the furnace or in air.