Milwaukee Step Drill Bit

Three step ranges are offered. The #3 (48-89-9203) steps 1/4 inch to 3/4 inch, the #8 (48-89-9208) steps 1/2 inch to 1 inch in 1/16 inch increments, and the #9 (48-89-9209) cuts 7/8 inch and 1-1/8 inch only. For electrical work, the #9 is the one that lands on the two common conduit knockout sizes, while the #8 gives you every sixteenth between 1/2 and 1 inch for mixed panel work.

The shank is a 3-flat secure-grip design, which gives the chuck jaws flats to bite rather than a round surface, so the bit resists slipping under load. The bits are also optimized for cordless drills run in high speed.

They are built for different materials. The Milwaukee 48-89-9208 step drill bit is a dual-flute black oxide step bit that walks up through stepped diameters from 1/2 inch to 1 inch in 1/16 inch increments, with laser-engraved reference marks so you can stop on a given hole size - the usual choice for thin metal, enclosures and panel work. The Lenox 12111-10DGHS is a 5/8 inch diamond grit drill bit in the D/S-10Dg series, an abrasive-cutting tool at one fixed diameter rather than a stepped cutter. If the job is a single 5/8 inch hole in hard, abrasive material, the diamond grit bit is the different tool; if you need multiple diameters from one bit in metal, the step bit is.

Each step carries a laser-engraved reference mark, so you can read the size off the bit as you go and stop on the step you need. That matters most on the #8, which has a step every 1/16 inch from 1/2 to 1 inch and is easy to run past.

A step bit cuts a range of sizes with one tool and self-deburrs as the next step passes through, which suits thin sheet metal, enclosures, and strut. A hole saw needs a separate size for every hole and a pilot. Where a step bit is the wrong tool is hard or abrasive material like tile, glass, or masonry, where you want a diamond grit bit such as the Lenox 12111-10DGHS in 5/8 inch instead.

It uses a dual-flute, jam-free geometry that keeps the cut controlled at breakthrough rather than letting the bit snatch, and the Rapid Strike tip starts the hole fast and straight without walking.

For a single fixed diameter, a one-size bit such as the Lenox 12111-10DGHS, a 5/8 inch diamond grit drill bit, does the job without stepping. The Milwaukee 48-89-9208 step drill bit earns its place when you are cutting a range of sizes - it covers 1/2 inch through 1 inch in 1/16 inch steps off one bit and one chuck change, with the 3-flat secure-grip shank to stop slippage and reference marks engraved on the steps so you stop at the size you want. Crews drilling knockouts at several diameters generally carry the step bit; a one-off hole does not require it.

Step up to the Milwaukee 48-89-9209, which cuts 7/8 inch and 1-1/8 inch. The 48-89-9208 tops out at 1 inch and the 48-89-9203 runs 1/4 inch to 3/4 inch, so for a 1-1/8 inch conduit or connector hole the 9209 is the one to stock. All three share the same dual-flute geometry and black oxide coating and are made in the USA.

Yes. Country of origin is the United States, which is what a government or institutional buyer working to a domestic-sourcing requirement needs on the line item.

The black oxide coating and the cut geometry are built to run cooler, which Milwaukee rates at up to 4X longer bit life, up to 2X faster cutting, and up to 50 percent more holes per battery charge compared with their previous design. Heat is what kills step bits, so running at high speed with steady pressure and no dwell is how you get that life.