Spring Collets Set Product Description 14-Piece Spring Collets Set with C20 ER20A 100L Collet Chuck Holder Unlock precision and performance in your machining projects with this comprehensive 14-piece Spring Collets Set. Ideal for CNC milling, boring, drilling, and more, this set provides the tools necessary for a variety of applications. Collet Specifications: Model: ER20 Material: Spring Steel Gripping Range: 1/8", 9/64", 11/64", 5/32", 3/16", 7/32", 15/65", 9/32", 5/16", 11/32", 3/8", 13/32", 7/16", 1/2" Upper Diameter: 28 mm Bottom Diameter: 25 mm Height: 34 mm T.I.R.: 0.0003" or 5µm Perfect for use in boring, milling, drilling, tapping, engraving, and CNC spindle machines Features finely polished surfaces with ground roughness of Ra0.4 microns Holder Specifications: Model: C20-ER20A-100L Material: 40 Chromium (40CR) Hardness: HRC46-50 Accuracy: 0.01 mm Shank Diameter: 20 mm Clamping Range: 1-13 mm Length: 100 mm Features: Precisely ground extension rod and components for superior balance and stability during operation. Direct nut tightening enhances grip and rigidity, providing powerful clamping force. Compatible with all ER20A collets, featuring a 20 mm diameter straight extended shank for deep processing. Improved balance due to precision-ground components, ensuring stability during cutting. High-rigidity clamping nuts for secure and strong clamping ability. Package Includes: 14 x ER20 Collets 1 x C20-ER20A-100L Chuck Holder For machinists seeking precision and versatility, this collets and chuck holder set offers reliability and high performance for your projects.