15Pcs Spring Collet 20CrMnTi Elastic Chuck Toolholder CNC Machine Tool BT40-ER32-15PC Item Type: Spring Collet Model: BT40-ER32-15PC Material: 20CrMnTi Purpose: CNC machine tools Specifications: 3-2,4-3,5-4,6-5,7-6,8-7,9-8,10-9,11-10,12-11,14-13,15-14, 16-15 ,17-18,20-19 Collet Length: Approx. 40mm / 1.6in Outer Diameter of Collet: Approx. 33mm / 1.3inHow e: 1. The groove of the spring chuck is loaded into the eccentric circle position of the nut, and the spring chuck is pushed in according to the direction indicated by the arrow, until the "click" represents the chuck is in place; 2. Install the spring chuck on the cutting tool again, and be sure to be in place; 3. Install the nut on the shank, and then lock it with a wrench; (It is recommended to tighten the nut with a torsion wrench)