Dremel 662 Glass Drill bit The Dremel Glass Drilling Bits are ideal for cutting holes in glass.     The Dremel Glass Drilling Bit 662 is ideal for cutting holes in glass. With the included cooling fluid you can drill perfect 6.4mm diameter holes. Technical specifications Shank diameter:     3.2 mm Working diameter:     3.2 mm Quantity     1 Order number     26150662JA