Cobalt Balls

Uses:
Cobalt balls are used in wear and high temperature applications, particularly where lubrication is marginal. ITI is capable of manufacturing cobalt balls in several alloys.  There are many trade names used for different alloys and often cobalt balls are referred to as Stellite balls Haynes balls, or Rexalloy balls.  The different alloy compositions are used for applications in valves, ball and seat, regulators, bearings and ball screws in many industries including petroleum and nuclear.

Ball Valves in Sub-Surface Oil Well Pump

 

 

Standard Material Chart

Material Analysis Cobalt 2 Cobalt 3 Cobalt 6 L-605 (Co-25)
Carbon 2.2/2.7% 2.00/2.60% 0.90/1/40% .05/.15%
Manganese 1.00% max. 1.00%max. 1.00% max. 1.00/2.00%
Silicon 1.00% max. 1.00% max. 1.50% max. 1.00% max.
Tungsten 16/19% 11.00/14.00% 3.5/5.5% 14-16
Chromium 31/34% 29.00/33.00% 26 19-21
Iron 3.00% max. 3.00% max. 3.00% max. 3.00% max.
Nickel 2.50% max. 3.00% max. 3.00% max. 9/11%
Other 2.00% max. 1.00% max. 2.00% max. .06% max.
Molybdenum 1.50% max.
Beryllium
Cobalt Balance Balance Balance Balance
Physical Properties of Cobalt Balls
Specific Gravity 8.80 8.69 8.46 9.13
Density lb/in. 3 0.317 0.314 0.305 0.330
Mechanical Properties of Cobalt Balls
(Cold Worked and Age Hardened)
Tensile Strength 40 KPsi 82 Kpsi 90 Kpsi 285 Kpsi
Yield Strength 60 Kpsi 44 Kpsi 78 Kpsi 45 Kpsi min
Elongation Nil Nil 1% 10% Typical
Rockwell Hardness R C 55-59 min. R C 51-58 min R C 39-43 40-50 Typical
Stock Availability of Cobalt Balls

    Available
Stock Sizes
Roundness
Dia. Tol/Ball
Basic Dia.
Tolerance
Surface
Finish
Material Ball Grade Inches Inches Inches Micro Inch
Cobalt #2 25 3/16 – 5/8 .000025 ±.0001 1.5
Cobalt #3 25 1/4, 3/8, 9/16 .000025 ±.0001 1.5
Cobalt 6, L 605 – Non Stock Alloys conforming to MIL – C – 24248 and Mil C – 24252 available on request.

Cobalt Balls Information Page