Climax Metal, H2C-Series: 2-Piece Recessed Screw Clamping CollarRecessed screw head provides an outside surface free of major projection for safety. Design fully engages the shaft without marring. Easily installed where major disassembly would otherwise be required. Greater axial holding power than set screw or one-piece clamping collars. Effective on hard and soft shafts. Bore SIzes 1/8" to 6" in Stainless Steel and Black Oxide Steel.