| There are essentially two choices for the material used in a ball bearing - 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. |
CHEMICAL COMPOSITION (%):
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 |
- |
Hardness: 60 - 64 Rockwell 'C' |
| |
| STAINLESS STEEL |
400 series martensitic stainless steel is the standard material for miniature and instrument ball bearings where corrosion resistance is more important than load capacity. There are 3 types of 400 series stainless steel used in the bearings described in this handbook. These materials have evolved in response to different manufacturing and application needs. It is important to note that the actual material used is generally determined by the manufacturer, and cannot be specified by the user |
DR Stainless steel
This material is used in the manufacture of most corrosion-resistant bearings. It has been specifically developed to give excellent lifetime and low noise characteristics, combined with superior corrosion-resistance. |
CHEMICAL COMPOSITION (%):
C
CARBON |
Si
SILICON |
Mn
MANGANESE |
P
PHOSPHOROUS |
S
SULPHUR |
Cr
CHROMIUM |
Mo
MOLYBDENUM |
.6 - .7 |
Max 1.0 |
Max 1.0 |
Max .03 |
Max .01 |
12 - 13.5 |
Max .25 |
Hardness: 58 - 60 Rockwell 'C' |
| |
