Dear Customer,Please notice that these diamond drilling bits’ thread is 5/8-11 not M14.
Usually these diamond drilling bits with 5/8-11 thread are used in North America like USA,Canada.
Diamond drilling bits with M14 thread are used in Europe market, such as Russia, Netherlands, Czech Republic a nd so on.
So please check and confirm whether you order the right thread or not.
Item : Vacuum brazed diamond Dry drilling bits(1/4"&3/8")
Specification : Diameter 6mm+10mm, 5/8-11