High quality, HSS Thunder Bits in 9/32", 11/32" and 13/32", jobbers length in stock. The slight oversize for 1/4", 5/16" & 3/8" holes in the mild steel helps the carbide and diamond core drills run cooler with less side friction and greater efficiency.
9/32 X 4-1/4" Strongarm Thunder BIt
11/32 X 4-3/4" Strongarm Thunder BIt
13/32 X 5-1/4" Strongarm Thunder BIt