For a 2-3/4 inch hole, you need a 2-3/4 inch hole saw — the saw’s diameter equals the hole’s diameter, which converts to 70 mm.
A hole saw cuts a circle the exact width of its own body, so the number on the package is the hole you get. That single fact removes most of the guesswork: a 2-3/4 inch hole saw bores a 2-3/4 inch opening, and manufacturers list that same size as 70 mm on their spec sheets. The harder part isn’t picking the diameter — it’s the two specs printed in smaller type that decide whether the saw actually finishes the job: cutting depth and arbor fit.
Does A 2-3/4 Inch Hole Saw Match A 70 mm Hole?
Yes — 2-3/4 inches is the same size as 70 mm on current manufacturer listings. DeWalt labels its DAH180044 as a 2-3/4-In. (70Mm) hole saw, and Milwaukee lists its 49-56-0731 as a 2-3/4″ HOLE DOZER with Carbide Teeth. A sizing chart converts 2-3/4 in to 69.85 mm, so the two numbers describe one opening.
That 0.15 mm gap is a rounding difference, not a size difference. It’s smaller than the tolerance of most drill presses, so don’t chase decimals — if a fixture calls for 70 mm, the 2-3/4 inch saw is the saw for it. Every other spec on a hole saw package is about how it performs, never how wide it cuts.
Cutting Depth: The Number That Actually Surprises Buyers
The listed cutting depth is the maximum thickness you can bore through in one pass, and it is always smaller than the saw diameter. Milwaukee’s 2-3/4″ HOLE DOZER with Carbide Teeth is rated at 1.62 in. cutting depth, while other 2-3/4″ saws in listings show 2 in., 2-1/8 in., or 1-5/8 in.
A 2-3/4 inch hole saw does not cut 2-3/4 inches deep. Buyers mix these two numbers up constantly, then wonder why the saw bottoms out halfway through a thick door slab. The fix is simple: compare the listed cutting depth against your material’s true thickness before you buy, and if the material is thicker, flip it and cut from the other side.
- 1-5/8 in. depth — enough for 2x lumber, drywall, and most plywood.
- 1.62 in. depth — Milwaukee’s carbide-tooth rating; handles a standard 2×4 with room to spare.
- 2 in. and 2-1/8 in. depth — deep-cut bodies for doubled-up panels or thick stock.
Two passes from opposite faces is the standard workaround for anything over the listed maximum. Mark the center point on both sides so the two cuts line up.
| 2-3/4″ Saw Example | Listed Depth & Arbor Fit | Typical Material |
|---|---|---|
| Milwaukee 49-56-0731 (HOLE DOZER, carbide teeth) | 1.62 in. depth; 5/8 in.-18 thread | Wood, composites, metal sheet |
| DeWalt DAH180044 | 70 mm listing; check arbor separately | Wood, plastic, drywall |
| M. K. Morse MHS44 | 5/8 in.-18 thread size | Bimetal cutting, general purpose |
| Bi-metal 2-3/4″ saws | Varies; 5/16 in. pilot drill common | Wood, plastic, thin metal |
| Carbide-tipped 2-3/4″ saws | Varies; 3/8 in. arbor shank | Masonry, tile, composites |
| Arbor-included kits | Matching arbor shipped with the saw | Mixed jobs, one-stop buying |
| Arbor-sold-separately saws | Verify thread size against your arbor | Pros with an existing arbor |
Will Your Arbor And Pilot Bit Actually Fit?
Not automatically — 2-3/4 inch hole saws use different arbor threads, so the saw must match the arbor you already own. Milwaukee and M. K. Morse listings show a 5/8 in.-18 thread size, some saws specify a 3/8 in. arbor shank, and others call for a 5/16 in. pilot drill.
Measure before ordering. If the saw and arbor mismatch, you’ll be holding a part that spins on nothing. A quick check of the thread size on your arbor against the saw’s spec line settles it in ten seconds.
One more split that matters: tooth type decides material, not just size. Bi-metal saws take wood, plastic, and thin sheet metal, while carbide-tipped saws are built for masonry, tile, and composites. Running the wrong tooth type on the wrong material burns through bits fast and shortens the saw’s life.
Once the diameter, depth, thread, and tooth type line up, hardware stores and online listings both carry plenty of matching options — check our tested 2 3 4 inch hole saw picks and comparisons if you want the shortlist already vetted. If you’d rather verify specs straight from the manufacturer, Milwaukee’s product pages list the full 49-56-0731 depth and thread specifications down to the decimal.
FAQs
Is 70 mm the same as 2-3/4 inches?
Very close. Manufacturer listings treat 2-3/4 inches and 70 mm as one size, and a sizing chart converts 2-3/4 inches to 69.85 mm. The 0.15 mm gap is rounding. For any practical job — cabinet doors, plumbing runs, recessed fixtures — the two labels describe the same hole.
Can I cut through a 2×4 with a 2-3/4 inch hole saw?
Usually yes. A 2×4 measures 1-1/2 inches thick, and most 2-3/4 inch saws list a cutting depth between 1.62 and 2-1/8 inches. Check your specific saw’s rated depth first — the shallowest models at 1-5/8 inches still clear a 2×4, but only just.
Do I need a separate arbor for a 2-3/4 inch hole saw?
It depends on the model. Some 2-3/4 inch saws ship with a matching arbor, while others sell the arbor separately and specify a thread such as 5/8 in.-18. If you already own an arbor, confirm the thread size matches before buying the saw.
References & Sources
- Milwaukee Tool. “2-3/4″ HOLE DOZER™ with Carbide Teeth Hole Saw.” Lists the 1.62 in. cutting depth and 5/8 in.-18 thread for the 49-56-0731.
- DeWalt. “2-3/4 In. (70mm) Hole Saw.” Equates the 2-3/4 in. diameter with 70 mm and gives the DAH180044 model listing.
- The Home Depot. “Milwaukee 2-3/4 in. Carbide Hole Dozer Saw.” Retail listing supporting current availability and specs for the Milwaukee saw.
