Metallics SD1231678 Drill Bit Spiral Flute Step 12 Step 3/16"-7/8" (1pc)

The SD1231678 is a 12 step bit covering 3/16 inch up to 7/8 inch. Each step cuts one size, so a single bit walks you from a small pilot hole up to 7/8 inch without swapping tools. Useful range for knockouts and clearance holes in sheet metal boxes, enclosures and panels.

That is the main use for it. The SD1231678 covers 3/16 inch through 7/8 inch in 12 steps, which spans the common clearance and small knockout sizes in thin gauge enclosures, device boxes and panel covers. Step bits self pilot and leave a round, burr light hole in sheet metal, where a twist bit tends to grab and triangulate. For heavy structural steel or deep stock, use a twist bit or a hole saw instead, since a step bit only cuts to the depth of each step flute.

No. The SD1231678 tops out at 7/8 inch, so it will not produce the larger openings needed for bigger conduit fittings. For those you need a step bit with a larger top step, a knockout punch set, or a hole saw sized to the fitting.

The SD1231678 uses a spiral flute. The spiral pulls chips up and out of the hole and gives a smoother, lower chatter cut, which is what you want when stepping through sheet steel or aluminum repeatedly. Straight flute step bits are simpler and cheaper but tend to load up with chips and run rougher on the larger steps.

One bit, supplied in a pouch. It is a single multi size step bit rather than a set, so the 12 steps from 3/16 inch to 7/8 inch all live on the one tool. The pouch keeps it from knocking against other bits in a pouch or truck bin.

Metallics catalogues the SD1231678 as an electrical tool item, and the 3/16 inch to 7/8 inch step range lines up with the clearance and small knockout holes electricians cut in boxes, panels, strut and enclosure covers. Nothing about it restricts it to electrical work, though, it cuts the same holes for HVAC sheet metal or general MRO sheet work.