The stained ceramic glass abrasive tool adopts a standard frosted design, and the Brass core reduces shaft binding and will not stick to the shaft of the grinder ,Made of quality copper material, and the surface is plated with diamonds, Diamond abrasive bonding surface is double plated , high strength, and long life Stained glass drills are suitable for forming and drilling of hard materials such as ceramic tiles, glass, colored glass, stone, etc., also proper for shaping most types of glass, ceramic tiles, stone and similar materials, and work well for glass grinders of most brands 4 Size: The drill bit is chrome-plated and hardened have 4 pieces of diamond grinding bits in 4 sizes, namely, 1 inch, 3/4 inch, 1/4 inch,1/8 inch，along with matching allen wrenches, different sizes and complete combination to fully meet your DIY use. Used for shaping and grinding all kinds of glass, stained glass, ceramic tile, stone, etc; Suitable for most glass grinding machine,Max speed 4200 RPM(When grinding, be sure to add water or coolant to use); It is a good choice for handmade enthusiasts and designers. Stained ceramic glass abrasive tool adopts a standard frosted design, and the brass core reduces shaft binding and will not stick to the shaft of the grinder; The drill bit is chrome-plated and hardened to improve performance, strength and durability Stained Glass Diamond Grinder Bit Head Tools Brass Core Stained Glass Grinder Bits & Diamond Grinder Bit Head Tools