Model RC, Rigid Shaft Couplings, are designed to join shafts that are in parallel alignment via precisely bored coupling halves. They are 2-1/2" long x 1-7/8" round and provided in a large range of standard bores to join any shaft to shaft combinations your application requires. Metric to inch couplings are available at your request. They are assembled radially over the shafts with 4 - 10-32 x 5/8" long socket caps screws. Rigid Couplings can used simply to join shafts to complete a drive or to allow a gap in line-shafting permitting quick belt changes in addition to installing change gears without major disassembly. They provide a very economical solution to join aligned shafts with high torsional stiffness, high torque capacity, and zero backlash. They are precision CNC machined from 6061-T6 extruded aluminum providing superior strength and tolerances. Due to these high tolerance standards and characteristics, they provide outstanding performance for precision motion control and servo applications. They are delivered ready to install and run.