Milwaukee Tool 48-89-9257 SHOCKWAVE™ Impact Duty ELECTRICAL KIT (#1, #4, #9)

The 48-89-9257 SHOCKWAVE Impact Duty electrical kit contains three step bits: the #1, #4 and #9. Each bit is laser engraved at the steps so you can read the stop-on size while you're drilling, which is what you want when you're punching a run of knockouts and can't stop to check a chart.

Both work. The SHOCKWAVE step bits are optimized for impact drivers but are drill/driver compatible, so an electrician carrying only a cordless drill can still run them. The Shockzone in the shank is tuned to absorb impact torque and reduce early shank breaks, so the impact driver is where the design pays off.

Step bits. Despite the SHOCKWAVE Impact Duty name being used across Milwaukee's driver bit line too, 48-89-9257 is a three-piece electrical step bit kit (#1, #4, #9) for drilling and enlarging holes in sheet metal, enclosures and panels. If you're after ratcheting screwdriver bits instead, the Klein Tools 32787S ProFlex Micro Ratchet 20-piece impact bit set is a driver-bit kit rather than a hole-cutting one.

They solve two different halves of an electrical job. The Milwaukee 48-89-9257 SHOCKWAVE Impact Duty ELECTRICAL KIT is a hole-making kit built around step bits in #1, #4 and #9 sizes, with a dual spiral flute and Rapid Strike Tip for fast, accurate starts and laser engraving so you can read the stop-on size while drilling. The Klein Tools 32787S is a 20-piece ProFlex micro ratchet impact bit set, so it is a driving set for fasteners rather than a step-bit kit for boring holes in panel and enclosure sheet metal. An electrician outfitting a van for knockouts and conduit holes wants the Milwaukee step bits; one who needs driving bits plus a ratchet for device and panel screws wants the Klein set.

Two things on the 48-89-9257 bits: a dual spiral flute paired with the Rapid Strike Tip, which Milwaukee rates at up to 2x faster holes than competitive impact step bits, and the tip geometry itself, which starts fast and accurate without a center punch wandering on sheet metal.

The bits carry a titanium aluminum nitride (TiBone) coating that Milwaukee rates at 5x longer life than competitive impact step bits. For a contractor drilling panel and box knockouts day in and day out, that coating is the reason to pick this kit over an uncoated HSS step bit.

Order Milwaukee 48-89-9257. That single MPN covers the complete three-bit electrical kit with the #1, #4 and #9 step bits; there are no separate size or finish options to specify.

Yes, if your work involves enlarging or creating holes. A driving set such as the Klein Tools 32787S ProFlex 20-piece impact bit set covers fastener driving with a micro ratchet, but it does not step-drill. The Milwaukee 48-89-9257 SHOCKWAVE Impact Duty ELECTRICAL KIT supplies #1, #4 and #9 step bits with a titanium aluminum nitride coating and an optimized Shockzone that reduces early shank breaks under impact driver torque. Most electrical MRO carts end up carrying both, one for holes and one for screws.

Yes. The SHOCKWAVE Impact Duty ELECTRICAL KIT bits are optimized for impact drivers but are drill/driver compatible, so a contractor without an impact on the ladder can still run them. That is a different use case from the Klein Tools 32787S ProFlex set, which pairs its bits with a micro ratchet for hand driving in tight gear and panel spaces where no powered tool fits.

Yes. The SHOCKWAVE Impact Duty step bits in the 48-89-9257 kit are made in the USA with global materials, which matters if you're buying against a domestic-preference spec on a government or institutional job.