In the metalforming machinery shop, with both chain and gear types, the erosive effects of rubbing  or sliding as it’s commonly called – occur between coupling elements during each revolution, depending on the angular shapes of connected shafts. Lubrication is needed to counter this sliding and prevent undue wear and tear.

Grease is the preferred choice for lubricating couplings, possessing qualities suitable for resisting possible shock loading. Essential to a successful application that works well between rubbing surfaces are a soft consistency and the ability to penetrate.

The chain type should be lubricated about once a month by applying grease with a brush. This interval is subject to modification as experience dictates and longer intervals may be just as satisfactory.

The gear type is packed with grease and relubrication is required only about once a year. At this time, the couplings should be taken down, the old grease completely cleaned out, and the coupling repacked with fresh grease.

Some users may prefer heavy oil for use in gear type couplings but more frequent attention will then be needed as there is always the chance that leakage will develop and leave the couplings devoid of lubricant.