Features Excellent Tungsten Steel Material: This stone carving set is made of excellent tungsten steel material with high hardness, heat and wear resistance, strong anti erosion effect and longer service life. Fine Groove Type: This grinding bit adopts fine groove type, with fluent chipping, no dust pollution, high concentricity, stable and reliable, applicable to more complex working conditions. Round Shank Design: This polishing rotary tool bit is designed with round shank, which is easier to clamp the tool correctly, and has a wide range of applications. Wide Application: This grinding burr bit set has a wide range of applications and can be used for mold processing and manufacturing, mechanical chamfering, chamfering and groove processing, cleaning burrs, burrs and weld seams of casting. Multifunctional: This burr bit is multifunctional and is suitable for sanding all kinds of metal, wood, copper and aluminum, plastic and other soft and hard materials. Specification: Item Type: Grinding Drill Bit Set Material: Tungsten Steel Applicable Machines: Electric Hand Drill ( Chuck 6mm or Above), Cordless Electric Hand Drill, Straight Head Electric Grinder, Benchtop Electric Drill Application Scope: Mold Processing and Manufacturing, Mechanical Chamfering, Chamfering and Groove Processing, Cleaning Burrs and Welding Seams of Casting and Forging Welding Pieces, Metal and Non Metal Materials Artistic Engraving Applicable Materials: All kinds of metal, wood, copper, aluminum, plastic and other soft and hard materials. Package List: 8 x Grinding Bits 1 x Storage Box  Note: Used on pneumatic or electric tools at 6,000 to 50,000 rpm. Package List 8 x Grinding Bits 1 x Storage Box