Three series are available: the W Series (metric) accommodates shaft sizes from 3 to 20 mm, the MC Series from 0.16 to 1.75 in., and the H Series from 0.06 to 0.75 in. All three series are capable of transmitting torque through 5° if required and can operate in temperatures up to 600°F (300°C).
Helical Products Co. Inc., Box 1069, Santa Maria, CA 93456, (877) 353-9873, heli-cal.com