... eco-friendly 3.size: 20x20.1mm 4.DIN JIS copper sleeve Specifications:1) Suitable for various automotive, electronic ... Japanese and South Korean high-precision CNC lathes, automatic lathes, automatic milling machines, centreless grinders, instrument lathes and accessories ... others optional can be as requirements6)Material: iron/aluminum, copper, alloy, carbon steel, 18CrMnTi,20CrMnTi,20Cr,20CrV,1045 ...