Come with or without keyways. Come with straight and stepped bores (inch only) for joining different diameter shafts. Develop a greater load than a single split shaft coupling, due to the eight socket cap screws vs. the four used in single split. Double split with keyway provide the greatest load available in a coupling application. Stepped bores available with and without keyways in inch. Inch, metric - steel, black oxide and bright finish stainless steel. Make sure you see our full selection of shaft couplings.