Metallics HSSC43E Drill Bit HD Cobalt St 135d SplPt 7/8" 7" YLW (1pc)

The HSSC43E cuts a 7/8 inch hole. Overall length of the bit is 7 inches, so usable flute depth is shorter than that once the shank is held in the chuck. It is a straight shank bit with a 135 degree split point.

Cobalt is the reason to pick this one. The HSSC43E is a heavy duty cobalt bit, which is the grade electricians and MRO crews reach for on hardened and work-hardening metals (stainless, strut channel, panel steel) where plain high speed steel burns up. Cobalt runs hotter without losing its edge, so it holds up on steel where a standard HSS bit dulls after a few holes.

Straight shank, not a reduced or hex shank. On a 7/8 inch bit the shank is sized to the bit, so plan on a drill press or a heavy half-inch or larger capacity drill rather than a standard cordless. Check your chuck capacity against the shank before you order; a 1/2 inch keyless chuck will not take a full-diameter 7/8 inch shank.

It self-centers. A 135 degree split point starts cutting on contact instead of skating across the surface, so you can drill sheet metal, strut or an enclosure wall without a center punch or a pilot divot. The flatter 135 degree geometry also spreads the cutting load, which matters on a hole as large as 7/8 inch.

For a 7/8 inch hole in panel steel or a box, the twist bit is the cleaner choice: it starts without a pilot thanks to the 135 degree split point and leaves a round hole sized for standard 1/2 inch trade conduit fittings. A hole saw or step bit is the better tool when you need several different diameters from one setup or you are going much larger than 7/8 inch. For repeated holes in stainless or hardened panel, cobalt is what survives.

It ships as one bit, a single 7/8 inch cobalt drill, supplied in a pouch rather than an index or case. If you are stocking a van or a shop crib and want a range of sizes, you order each diameter separately.