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Ball Bearing Material

BALL BEARING MATERIALS
There are essentially two choices for the material used in ball bearings - chrome steel or stainless steel. Since the material plays a major part in the performance of a bearing in any given application, it is very important that the correct material is used. Note that the specified material applies to the load bearing components only - the rings and the balls. The retainer and the shields (if used) are usually made from a different material and are subject to separate specification.
CHROME STEEL (AISI 52100 OR EQUIVALENT)
This is the standard material used for ball bearing applications where load capacity is the main consideration. The machinability of this steel is excellent, giving smooth, low noise raceway finishes, together with superior life. Chrome steel material is recommended in applications where corrosion is not a factor.
C
CARBON
Si
SILICON
Mn
MANGANESE
P
PHOSPHOROUS
S
SULPHUR
Cr
CHROMIUM
Mo
MOLYBDENUM
.95 - 1.1 .15 - .35 Max .5 Max .025 Max .025 1.3 - 1.6 -
AISI 440C STAINLESS STEEL
The use of 440C material has declined in favor of other, more modern stainless steel formulations. However, it is still widely available and has very high resistance to corrosion.
C
CARBON
Si
SILICON
Mn
MANGANESE
P
PHOSPHOROUS
S
SULPHUR
Cr
CHROMIUM
Mo
MOLYBDENUM
.95 - 1.2 Max 1.0 Max 1.0 Max .04 Max .03 16 - 18 Max .75
AISI 304 STAINLESS STEEL
Higher corrosion resistance than AISI 440C stainless steel ball bearings
Specic Gravity Tensile Strength(N/mm2) Elongation Elastic Modulus(N/mm2) Hardness Magnetism
7.93 520 ~ 600 45% ~ 60% 193000 170 HV
3.0 HRC
Non magnetic*1
AISI 316L STAINLESS STEEL
Better corrosion resistance than 440c, 304 stainless. Resists sodium and calcium brines, hypochlorite solutions, phosphoric acid, sulfite liquors and sulfurous acids that are commonly used in the paper pulp industries.
Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Nitrogen Molybdenum
Maximum of 0.080% Maximum of 2.00% Maximum of 0.045% Maximum of 0.030% Maximum of 1.00% 16.00% to 18.00% 10.00% to 14.00% Maximum of 0.010% 2.00% to 3.00%