AEGIS® Tools recommends this Cross-cut Fissure Burr as one of our best bits for drilling and excavating rock chips. The cross-cut design efficiently creates a pathway for resin flow while running cooler than other burrs, resulting in longer service life. These bits come five to a pack. Be sure that you change out your burrs after 10 to 15 uses if the bit isn't penetrating the break. These burrs are designed for use with a 1/16 inch (1.5 mm) Collet (part DRL5032, sold separately). Purchase a 5 pack of our Cross-cut Fissure Burrs today for your glass business.