Features： 1、Multi Purpose:Extended tungsten steel grinding head is ideal for fine detailing, cutting, carving, retouching and more. 2、High Hardness: Lengthened tungsten steel grinding head is made of tungsten steel, and the hardness of the grinding head reaches HRC70. 3、Applicable Tools: Tungsten steel grinding head is usually used with hand held, electric or pneumatic tool drivers (can also be used in machine tools). 4、Easy to Replace: Porting tools can replace old broken grinding heads, the maximum cutting diameter is 8mm, 10mm. 5、Wide Application: The grinding head set is suitable for grinding and polishing cast iron, carbon steel, alloy steel, stainless steel and other materials. Specification： Item Type: Rotating Burr Material: Tungsten Steel Color: Silver Shank Type: 6mm Round Shank Maximum Cutting Diameter:Approx. 8mm / 0.3in,Approx. 10mm / 0.4in Grinding Head Hardness: HRC70 Product Length:Approx. 150mm±10mm / 5.9in±0.4in(the Length is within This Range) Applicable Scene: Hand Held Electric or Pneumatic Tools (can Also Be Used in Machine Tools) Package List： 4 x Rotating Burr  4 x Storage Box