Stellite 6 is the most widely used of the wear resistant cobalt-based alloys and exhibits good all-round performance. It is regarded as the industry standard for general-purpose wear resistance applications, has excellent resistance to many forms of mechanical and chemical degradation over a wide temperature range, and retains a reasonable level of hardness up to 500°C (930°F). It also has good resistance to impact and cavitation erosion. Stellite 6 is ideally suited to a variety of hardfacing processes and can be turned with carbide tooling. Examples include valve seats and gates, pump shafts and bearings, erosion shields, and rolling couples. It is often used self-mated.

Stellite 6 Chemical Composition, %:

Co	Cr	W	C	Ni	Fe	Si	Mn
Balance	27.0-32.0	4.0-6.0	0.9-1.4	3.0	3.0	1.5	1.0

Mechanical Properties of Stellite 6:

At Room Temperature, Investment Castings As Cast

Ultimate Tensile Strength	790 Mpa
Yield	(0.2 % offset) 660 Mpa
Elongation	< 1 %

Stellite 12 is a cobalt-base alloy having high heat and corrosion resistance with excellent wear and abrasion resistance. Examples include industrial knives for cutting carpets, plastics, paper and synthetic fibers; and saw tips in the timber industry. It is also used for control plates in the beverage industry, pump vanes, bearing bushes and narrow neck glass mold plungers; and for hardfacing of engine valves, pinch rollers in the metal-processing industries and rotor blade edges. It contains a higher fraction of hard, brittle carbides than Stellite 6, and has increased resistance to low angle erosion, abrasion, and severe sliding wear whilst retaining reasonable impact and cavitation resistance. The higher tungsten content provides better high temperature properties compared to Stellite 6, and it can be used at temperatures up to about 700˚C.

Stellite 12 Chemical Composition, %:

Co	Cr	W	C	Ni	Fe	Si	Mn
Balance	27-32	7.5-9.5	1.4-1.7 (hardfacings) 1.7-2.0 (castings)	1.5	3.0	0.7	2.5

Mechanical Properties of Stellite 12:

At Room Temperature, Investment Castings As Cast

Ultimate Tensile Strength	740 Mpa
Yield	(0.2 % offset) 580 Mpa
Elongation	< 1 %

Stellite 25 Chemical Composition, %:

Co	Ni	Cr	Mn	Si	Fe	S
Balance	9.0-11.0	19.0-21.0	1.0-2.0	0.4 max	3.0 max	0.03 max

Stellite 25 ASTM Specification:

Sheet / Plate	Bar	Forgings
AMS 5537	AMS 5759, ASTM F90	AMS 5759

Mechanical Properties of Stellite 25:

At Room Temperature, Castings As Cast

Ultimate Tensile Strength	925 Mpa
Yield	(0.2 % offset) 895 Mpa
Elongation	1-2 %