BHA Tungsten Carbide Burr Rotary Files Grinder Bits, Aluma Cut - 1/4 Inch Shank

The flutes are affixed to the 1/4” shank during a soldering and sintering process that uses silver, which preserves the cobalt content thus increasing each burrs lateral strength and durability. Aluma (A.K.A. Aluminum or Non-Ferrous).