SHAFT RECOMMENDATIONS

Shafting

Since the shaft surface significantly affects the operation of the journal bearing design, its selection in regard to material, hardness, coating and surface roughness is crucial.

High loads require smooth surfaces with hardened and heat treated shafts. With stress levels of 8,000 to 30,000 psi shafting should have a surface finish of 8 micro inch or better to achieve optimum performance. However, tests have been run on 25-30 micro inch finishes with 55 Rc shafts at 4,000 psi with acceptable results.

Shafting Materials

A number of shaft materials have been used in conjunction with Duralon bearings:

1. 52100 high carbon steel
2. 4140 chrome and nickel plated steel
3. 300 and 400 series stainless steel
4. Precipitation hardened grades 17-4PH, 15-5PH, 13-8PH Moly chrome and nickel plated stainless steel
5. 2000 and 7000 series aluminum grade hard anodized
6. Low to high carbon steels

Surface roughness values do not define the character of the finish. Polished shafting (right) normally produces longer life.