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.
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 |
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Stock Availability of Cobalt Balls
| |
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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. |
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Cobalt Balls Information Page
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