Review on Climax RC 031 Plating Coupling Length by Rusty Calcara

Fits snugly but fits .3125" stems snugly with my caliper. Climax Part RC-031 Mild Steel, Black Oxide, 5/16" Bore 5/8" OD is perfect for my existing shafts. I mounted the shafts to this coupling with a tight fit, basically with no play (before you even tighten the bolts). I'm not sure if I have 8mm shafts or 5/16" shafts, I have several of these from a printer cartridge. My shafts are .3125" which is exactly 5/16" and this coupling fits perfectly. I was very impressed. It's not loose at all. I'm planning to use this to connect 2 shafts together to extend the motor shaft. The fit and finish is very high quality. PS I have a 5/16" aluminum coupler from Ordered from eBay from a US supplier, different seller, and it doesn't fit at all, it's too small to slide on the shafts. However, this Climax Part RC-031 Steel, Mild Steel, Black Oxide, 5/16" bore and 5/8" OD is perfect for the shafts I have.