Feature: 1. Significantly increases the contact between multiple shafts and the center hole surface, increases the clamping force and pressing area, thereby providing greater supporting force to withstand heavy radial loads. 2. There is a clamp bolt on each side. The balanced adjustment of the double bolt will produce a balanced and firm clamping force on the shaft to ensure that the components fixed on the shaft will not move or become loose. 3. Based on the center hole, the weight and volume are balanced. In high-speed applications, it can effectively avoid centrifugal force and vibration caused by unbalanced mass and volume of parts. 4. Fixing and clamping are completely independent, so the heavy-load shaft clamp can be installed in the workpiece spline and can be installed where other clamps cannot be installed. 5. The clamp is made of high quality aluminum, which has high hardness, wear resistance and durability. The parts are fixed by clamping without damaging the parts. Specification: Item Type: Hex Clamp Hub Material: Aluminum Alloy Model: 3311-0016-2005 Center Hole Size: Approx. 5mm / 0.2in (hexagonal hole) Thread: M4 Purpose: to connect the shaft and column by clamping without damaging the fixed parts Package List: 5 x hexagonal clamping hub Note: It is necessary to match the size of appropriate design before installation and use.