Dewalt diamond core bit is designed for high speed drilling and long life in a wide range of building materials. For use with diamond drills. Standard 1-1/4 Inch UNC female fitment to allow usage with Dewalt and other diamond drill brands. Length (mm): 500mm. Outer Diameter (mm): 107. Spindle Thread Size: 1 1/4 Inch UNC(F). For Use with: For use with diamond drills. Application: For dry drilling clean large diameter holes in masonry and stone. D107X1 1/4" UNC(F)XL500XT3.5MMXW10.