One of AEGIS® Tools bestsellers are these Carbide Burr bits for drilling rock chips. It is a solid, durable bit that the technician can use to excavate the break prior to delivery of the resin. 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 10 pack of our Carbide burrs today for your glass business.