standard connecting links are used when roller chains are operated under normal conditions. for severe applications, press fit connecting links are suggested.
Keyways are British Standard Metric B S 4235. Part 1: 1972 DIN 6885 and conform to ISO recomendations with the exception of those marked, which are shallower. Where a key is to be used it should be parallel and side fitting, with top clearance. Depth of keyway is measured at the CENTRE