Features ALUMINUM ALLOY: Shaft collar is made of premium aluminum alloy material, lightweight, oxidation resistant, corrosion resistant, durable and rugged. EASY INSTALLATION: The clamping shaft collar design fully grasps the axle without damaging the appearance. Easy to install, otherwise require large scale disassembly. ADJUSTABLE CLAMPING: Aluminium alloy shaft collar allows the shaft to be clamped by adjusting screws without damaging the shaft. APPLICABLE SCENARIO: The shaft collar with 20mm hole diameter is used for shaft fixing and positioning, linear motion stop and drill fixing. WIDE APPLICATION: Shaft collar is suitable for transmission assembly, motor base, machine tool, drive shaft, farm tools, paper and steel plant equipment, automotive industry, industrial, amateur craft industry, etc. Specification: Item Type: Shaft Collar Material: Aluminum alloy Inner Diameter: Approx. 20mm / 0.79in Outer Diameter: Approx. 40mm / 1.57in Thickness: Approx. 12mm / 0.47in Screw Hole: M4 Package List:4 x Shaft Collar Package List 4 x Shaft Collar