PM M48 high-speed tool steel is a flexible steel that provides a unique combination of high wear-resistance with high impact toughness and bend strength, which are results of the fine grain size, small carbides and superior cleanliness of the steel. PM M48 offers improved cutting tool life compared to conventionally-wrought M1, M2, M7 and other lower-alloyed high-speed steels. It excels in cold work tooling applications, outlasting high-carbon, high-chromium die steels such as D2 and D3.
Other Known Names: ~1.3207, CPM REX 76®, ASP 2048, HS 10-5-3-9, SKH 57
Griggs Steel Color Code:White
Common Usage
Broaches, End Mills, Form Tools, Hobs, Tabs, and Cut Off Blades.
Physical Properties
Density
0.298 lb/in3 (8256 kg/m3)
Specific Gravity
8.26
Modulus Of Elasticity
31 x 106 psi (214 GPa)
Machinability
10-15% of a 1% carbon steel
High Speed Steel Properties Comparison
PM M48 High Speed Steel Chemical Composition
| Maximum | Typical | ||||||
|---|---|---|---|---|---|---|---|
| Carbon | Chromium | Tungsten | Molybdenum | Vanadium | Cobalt | Annealed | Tempered |
| C | Cr | W | Mo | V | Co | Hb | HrC |
| 1.5 | 3.75 | 9.75 | 5.25 | 3.1 | 8.5 | 310 | 68 |
PM M48 High Speed Steel Heat Treating
| Annealing | Preheat | Austenitizing | Quench | Tempering |
|---|---|---|---|---|
| Temp | Temp | Temp | Medium | Temp |
| °F | °F | °F | °F | |
| 1550/1600 | 1500/1550 | 2150/2175 | Salt/Oil/Atm | 1080 |
PM M48 High Speed Steel Thermal Treatments
- Furnace: 2125-2220°F (1163-1204°C)
- Salt: 2100-2190°F (1149-1199°C)
Soak 3 – 10 minutes depending on the temperature.
To maximize toughness, use the lowest temperature
To maximize hot hardness, use the highest temperature.
For pressurized gas, the furnace should have a minimum quench pressure of 4 bars. A quench rate of approximately 400°F (222°C) per minute to below 1000°F (538°C) is critical to obtain the desired properties.
For oil, quench until black, about 900°F (482°C), then cool in still air to 150-125°F (66-51°C).
For salt maintain at 1000-1100°F (538-593°C), equalize in the salt, then cool in still air to 150-125°F (66-51°C).
Typical temperature range is 1000-1100°F (538-593°C). Do not temper below 1000°F (538°C). Hold at temperature for 2 hours then air cool to ambient temperature. Triple tempering is required. Quadruple tempering is required when austenitized at 2175°F (1190°C) or higher.
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 (15°C per hour) to 1000°F (538°C). Continue cooling to ambient temperature in the furnace or in air.