Large precision angular ball bearings are assembled on the front part of this NSK spindle to provide rigidity on both the radial and the thrust sides. This spindle is suitable for grinding of deep hole, grinding by ø1.57" (40mm) grindstone and small-diameter end milling.• Allowable Motor Speed: 30,000 rpm• Spindle Accuracy: Within 2 µm• Standard Size Collet Chuck (CHK-3.175): ø1/8"• Weight: 13.50 oz.• NSK Catalog Number: AS42511 (NR310)• Replaces older NR-310 spindles.Included Equipment:• Collet Chuck ø1/8" (CHK-3.175): 1 pc.• Chuck Nut (K-265): 1 pc.• Wrench (12 x 14): 2 pcs., (20 x 24): 1 pc.Optional Equipment:• Collet Chuck (CHK-[][]): ø0.5 mm~ø6.0 mm in 0.1 mm increments and 2.35mm, ø1/8", ø1/4"• Chuck Nut (K-265): For Collet Chuck (CHK)• Metal Saw Arbor (KCH-03): For ø0.24" (I.D.) x ø1.18" (O.D.)• Drill Chuck Arbor (DCH-J0K): For Jacob's Taper No. 0• Grindstone Flange (NGF2-19): ø19.05 (I.D.) x ø40 (O.D.) x 7 (W) mm