The flange coupling is made of 45 steel (a kind of iron), hardened by heat treatment, and then plated.
Note: The four screw holes at the lower part of the flange coupling are recommended to be fixed with M3 screws, instead of M4 because the M4 cap will be stuck to the flange edge.
Model: Flange coupling
Material: 45 steel
Surface Treatment: Electroplate
Size: 3mm , 3.17mm , 4mm , 5mm , 6mm , 6.35mm , 7mm , 8mm , 10mm , 11mm , 12mm , 14mm.