Core Cut First-Cut BASIC 3000 Concrete Diamond Blade - Medium Hard Aggregate First-Cut blades are part of the True Early Entry System for cutting control/relief joints in green concrete. Features Sold individually or packaged with skid plate Optimal time of cutting, known as the Control Zone, is 2 hours after finishing and before final set Cutting in the Control Zone is the best guarantee for the prevention of random cracking Designed for cutting green concrete with medium hard aggregate For use on Early Entry Walk-Behind Saws Good quality, long life cutting Includes 1" arbor with drive-pin hole and triangle knock out