1. A great combo of Sioux Valve Seat Grinding Stones Set Of 10 Pcs For 11/16" Thread 80 Grit with 45 degree angle. 2. Set contains 1 piece of each Sizes: 1-1/8" , 1-1/4" , 1-3/8" , 1-1/2" , 1-5/8" , 1-3/4" , 1-7/8" , 2" , 2-1/4" , 2-1/2". 3. The Stones can be dressed to any angle with Thread Intact. We made heavy duty stones of thread size of 11/16" 4. Verified Bond 80 Grit medium aluminum oxide pink Stones with Diameter of 0.69 Inches.