One-piece rigid couplings from Ruland do not mar the shaft and have high torsional holding power. They are supplied with proprietary Nypatch anti-vibration coating, which allows for repeated installations, prevents screws from coming loose during operation, and provides the necessary dissimilar material in stainless steel couplings to reduce galling. Straight bore rigid couplings from Ruland are precision honed to ensure bores are collinear. This is important when the rigid coupling is used in a precision servo system as honing allows for greater surface contact with the shaft and higher torque transmission capabilities. Ruland manufactures one-piece rigid couplings in 1215 lead-free steel with a proprietary black oxide finish, 303 stainless steel, and lightweight 2024 aluminum.