DimensionsTwo spot weld drill bits are 65mm (2.26 inch) and 79mm (3.11 inch) long High QualityMade of High Speed Steel containing Cobalt , strong and durable, rust-proof and heat-resistant, stable performance Unique DesignThe tip of the drill head is designed for more precise operation and to prevent slipping during use OperationSimply install the drill bit on the spot probing air drill, and the welding spot can be easily removed ApplicationMainly used in automobile repair and construction work. bodywork to eliminate welding points in boron and other materials Product Parameters: HSS Co 6 Drill Size: 65mm*4.8mm (2, 56''*0.19'') HSS Co 8 Drill Bit Size: 79mm*6.9mm (3.11''*0.27'') Material:Cobalt High Speed Steel Warm Tips: Please allow slight errors in d in the product size and color due to difference in measurement methods and display screens.