The SINOAXISSPACE SBR20 Shaft Collar is a high-quality stop collar designed for use on linear rails and motion guide shafts. With a bore of 20mm, outer diameter of 40mm, and thickness of 12mm, it offers precise positioning and secure clamping for industrial applications. This aluminum alloy shaft collar is durable, rust-resistant, and features an M4 set screw for easy adjustment. Ideal for CNC machines, 3D printers, and automation systems, the clamp-on design ensures a firm grip, preventing slippage. Perfect for linear motion systems, it enhances stability and accuracy during operation.