Features: , A full range of ER Type A sizes are available: ER8A, ER11A, ER16A, ER20A. Provide a full range of tool holder diameters: 8mm, 10mm, 12mm, 16mm, 20mm, 25mm. The advanced vacuum quenching furnace can achieve carbon and oxygen co-permeability, increase the hardness of the tool shaft, increase the service life, and tighten the holding force. Made of 40CrMnTi stainless steel alloy.Hardness HRC 58-62.Hardened and precise substrate. Extremely long avoidance of the ER extension can lead the cutter to the deep processing cavity of the processing cavity. Designed for ultra-precise and fast applications. Product Parameters:Color: as shown in the picture Material: Alloy Steel Max Speed: 30000rpm Runout: About 0.01mm Optional Specifications: C8-ER8A, C10-ER8A, C10-ER11A, C12-ER8A, C12-ER11A, C12-ER16A, C16-ER11A, C16-ER16A, C16-ER20A, C20-ER11A, C20-ER16A, C20-ER20A, C25-ER16A, C25-ER20ANa Example:C16-ER20A-100L:Straight Shank Size: 16mm Handle Size: ER20A Nut Type: A Type Handle Length: 100mm Packing List:1*Straight Shank ExtensionNote:1. The actual colors of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.2. Please allow slight manual measurement deviation for the data.