These are used for cutting the cavity needed for a coil spring pocket.
For metal hole making, our coil spring cutters provide fast, accurate, burr-free holes in steel materials up to 3/16" thick. These are annular cutting tools that cut around the edge of the hole and eject the center as a slug. Because they're hollow, there's no dead zone as with twist drills. Unlike hole saws, that rip and tear through the material, they quickly give you a quality, virtually burr-free hole. Our coil spring pocket cutters are available in 3 sizes for 1/4" and larger drill chucks. Spring loaded replaceable arbor pilot "pops" the slug from the cutter. These cutter bits are very nice.
(400rpm with lube recommended for tool steel)
Made in the USA