splines on the inner surface of the center sleeve are engageable with splines on the outer surface of the shaft and the splines on the outer surface of the center sleeve are engageable with splines on the inner surface of the mating sleeve exemplary embodiments of this invention are useful in downhole tools to reduce make up torque requirements of the mating sleeve and therefore may advantageously increase the cyclic torsional and or bending load capacity of the shaft while also increasing the total torsional load capacity of the connection application_number US 87360604 A description fig2 schematically illustrates one exemplary embodiment of a connector assembly 100 according to this invention in use in an offshore oil and or gas drilling assembly generally denoted 10 in fig2 a semisubmersible drilling platform 12 is positioned over an oil or gas formation not shown disposed below the sea floor 16 a subsea conduit 18 extends from deck 20 of platform 12 to a wellhead installation 22 the platform may include a derrick 26 and a hoisting apparatus 28 for raising and lowering the drill string 30 which as shown extends into borehole 40 and includes a drill bit assembly 32 and a downhole steering tool 200 including one or more force application members 232 steering tool 200 is shown coupled to a downhole sub 50 e g a cross over sub or a section of drill pipe via connector assembly 100 it will be appreciated.