IDEAL Industries Bi-Metal Hole Saw Kit

Three kit configurations: an 8-piece kit (36-500), a 14-piece kit (36-501), and a 19-piece kit (36-502). All three use the same bi-metal saw construction, so the choice is purely how many cup sizes and arbor pieces you want on the truck.

They are bi-metal cups built from M42 high speed steel with 8 percent premium cobalt, which is the grade used for cutting metal. The 4/6 variable pitch tooth geometry with fleem ground teeth handles both sheet metal, like steel studs and enclosure walls, and wood or plastic without changing cups.

Two features handle slug removal. Cat's eye openings in the solid back plate let you drive a punch or screwdriver through from behind, and they are present on the 2 inch through 6 inch cups. The diamond side openings, on the 7/8 inch through 6 inch cups, let you pop the plug out from the side. The smallest cups below 7/8 inch have neither, so plan on clearing those with a pick.

For a van kit that mostly drills studs and plates for conduit and cable, the 8-piece (36-500) covers the common sizes. Crews that also cut recessed can openings, large knockouts, and panel penetrations are reaching for cups up to 6 inches, which is where the extra sizes in the 14-piece (36-501) or 19-piece (36-502) pay off. Cup construction is identical across all three, so there is no performance difference, only coverage.

The cup range tops out at 6 inches, with the cat's eye and diamond side slug-removal features running up to that size. If you need a larger opening than 6 inches you are into a different tool entirely, typically an adjustable circle cutter or a sheet metal nibbler.

The cups are built on a rigid solid steel back plate rather than a stamped thin plate, which is what keeps the cup from flexing and walking when you are loading it off-axis or working overhead. The variable 4/6 pitch also reduces chatter at the start of the cut.