This is an item for business contractors. This product is especially effective for processing that requires precision using a precision cutting machine with an extra level of precision. Compatible work: High hardness steel; Compatible material examples: High speed steel (SKH), Chrommolybdenum steel (SCM), Special steel (SMCM); Abrasive material: HA, Outer diameter: 8.1 inches (205 mm); Thickness: 0.03 inches (0.8 mm); Inner diameter: 1.0 inches (25.4 mm); Quantity: 25 pieces