1/8" Drilling & Grinding BitInland 1 8" drilling bit. Use with bit adapter (part #40317 sold separately). Screw this grinding bit into the top of the adapter and you are ready to drill 1 8" holes or create fine details in your next stained glass project. Standard 120Grit for multi task use. Like all Inland bits, the brass cores are manufactured on "Swiss precision" machinery for consistent and accurate tolerances. Bits are measured for true before the diamond is applied, so the