Lightweight construction and cooler running design enhances the performance and life of these B&J rubber cutting gouges. The razor-like surface quickly removes large quantities of rubber. Fast and easy rubber removal design minimizes operator fatigue and permits better control. Micro Rotary Gouge, 3/4″, 20mm diameter, 3/8″, 10mm threaded arbor hole. 4 per box. Lightweight construction and cooler running design enhances the performance and life of these B&J rubber cutting gouges. The razor-like surface quickly removes large quantities of rubber. Fast and easy rubber removal design minimizes operator fatigue and permits better control. 1/2″, 15mm to 3/8″, 9mm Reducer