Air Tools Air Die Grinders Pencil Die Grinder 1/8 Inch Collet. Pencil Die Grinder 1/8 Inch Collet. Model No. 5978A Features: Twist throttle ... Straight Air Die Grinder 23,000 RPM 1/4 Inch Collet HP Manufacturers Part #: SDG05S23 ... 1/8 IN MICRO GRINDER