Hard carbons for bearings and bushings

Q. Hard carbon materials are available; will they perform better GRAPHALLOY(r) for bushings?

A. Carbon materials can be made over a wide range of hardnesses - from soft brush materials to nearly ceramic hard mechanical seal face materials. Hard carbons can be much harder than usual shaft materials. These hard carbons can score shafts to the point where the shaft is actually cut.

Bushings, especially those internal in pumps, are intended to be wear parts, absorbing the shocks, rubbing and abrasion of normal use without damaging the shafting. GRAPHALLOY is chosen for pumps to provide non-galling, self-lubricating bearings.

GRAPHALLOY with a moderate hardness is used in most pump applications to ensure that expensive shaft materials will be protected.