Jaw Couplings - Sizes 19 to 48 are now in stock, bored and keyed and ready to be delivered. These are low cost, no fuss shaft couplings. The JAW shaft couplings are available in steel, cast iron and aluminium and can come with ATEX approval if requested. To suit shaft sizes from 6mm to 100mm or supplied pilot bored. The curved jaw coupling design consists of an elastic “spider” and two hubs. The spider, made of an advanced polyurethane material, provides dampening of impulse loads, minimizing shock to the motor and other sensitive equipment.