Diamond Bits 20-50mm Cone Beveling Chamfer Bits For Holes Countersink CeramicElectroplated Diamond 20-50mm Cone Chamfer Grinding for Head Stone Glass Chamfering for Head Sanding Tool Accessories Features: Diamond coated Taper Single type angle drills, use to machine chamfer hole of glass, stones etc. Suitable for use in grind the edge of glass, marble, rock, gemstone, jewelry, shells, tile etc. Use with water as a lubricant is better. Specification: Type: Cone Grinding Bits Material: Diamond Applications: Grinding Features: Cone Grinding Bits, Electroplated Diamond, Glass Chamfering, Chamfering Sanding, Tool Accessories Dimension: 20: app.2cm/0.79in 25: app.2.5cm/0.98in 30: app.3cm/1.18in 35: app.3.5cm/1.38in 40: app.4cm/1.57in 45: app.4.5cm/1.77in 50: app.5cm/1.97in Color: Silver Quantity: 1 Pc Note: 1.Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Package includes: 1 Pc x Cone Grinding Bits