Check the listing for details. MR-13A Drill Bits Grinder Grinding Machine 2-13 mm 100-135 Angle fast ship. Condition: New. Listed at 493.98 USD. Portable idiot drill grinder, twist drill grinder. Grinding is accurate and rapid, easy operation with no skill to grind. Grinding Range. grinding wheel :CBN (for HSS)×1. Eleven collets: ф3 、 ф4 、 ф5 、 ф6 、 ф7 、 ф8 、 ф9 、 ф10 、 ф11 、 ф12 、 ф13.