VEVOR 13 pcs Precision R8 Collet Set, 1/8'' - 7/8'', 45# Mill Collet Chuck 0.0012"/30μm TIR with 13 Labeled Storage Boxes, for Milling Machine Drill Presses Boring Machine Machining CenterProduct Features Standard Size Our R8 collet chucks are designed to clamp diameters ranging from 1 8" to 7 8". The drawbar thread is 7 16" 20 UNF, and the precision is an impressive 0. 0012 in 30 m, ensuring top notch accuracy for your machining needs. Internal Thread Design Our R8 collet chucks feature an internal thread design that makes it easy to tighten end mills. Whether you're cutting keyways, securing double ended end mills, or tackling any