M50 Steel (AMS 6491, AMS 6490)
M50 is a premium-melted alloy exhibiting excellent resistance to multi-axial stresses, resistance to softening at high service temperatures and good resistance to oxidation. Characteristic of a high-speed tool steel, it possesses high compressive strength. All M50 at Sullivan is melted in the USA. Domestic Source and DFARS Approved.

FOR REQUIREMENTS: | High Temperature Steel, Aircraft Bearings |
MELT PRACTICE: | VAR & VIM-VAR |
SPECIFICATIONS: | AISI Type M50 AMS 6491 (VIM-VAR) AMS 6490 (VAR) Reference UNS K88165 |
Benefits of M50
- Exhibits excellent resistance to multi-axial stresses and softening at high service temperatures as well as good resistance to oxidation
- Characteristic of a high-speed tool steel, it possesses high compressive strength.
- Due to the alloy’s high degree of cleanliness, parts are capable of being finished to a high luster.
- Used in a wide variety of applications for components which require high wear resistance and strength at elevated temperatures
Typical Applications
- Aircraft Engine Bearings
- Helicopter Rotor Bearings
- Gas Turbines (requiring hot hardness)
- High Performance Racing Engines
- Tooling Applications
Chemical Composition – VIM-VAR
C | Cr | Si | Ni | V | W | Mn | Mo | S | P | Co | Cu | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
min. | 0.80 | 4.00 | – | – | 0.90 | – | 0.15 | 4.00 | – | – | – | – |
max. | 0.85 | 4.25 | 0.25 | 0.15 | 1.10 | 0.25 | 0.35 | 4.50 | 0.008 | 0.015 | 0.25 | 0.10 |
Stocking Sizes
Bar: 0.200″ – 8.000″ø
Wire: 0.185", 0.276", 0.354"ø
GET M50 AT SULLIVAN STEEL