Hole Saw Arbor Compatibility: Which Arbors and Cups Actually Fit Each Other
Hole saw arbor compatibility is mostly a solved problem. Almost every cup above 1¾" in diameter uses the same thread — 5/8"-18 UNF — and Milwaukee, DeWalt, Bosch, and Lenox all share it. That means a Milwaukee Hole Dozer cup will thread onto a DeWalt arbor, and vice versa. The one wrinkle: Milwaukee's quick-change arbors add a notch-lock mechanism for fast cup swaps, but that feature only works with Hole Dozer cups that carry the matching notch. Any other cup threads on and cuts normally — it just won't quick-change.
That's 90% of the compatibility question settled. The rest comes down to which shank matches your drill or impact driver.
The Thread Standard — Why Most Hole Saws Are Cross-Brand Compatible
5/8"-18 UNF: What It Means and Who Uses It
The 5/8" is the outside diameter of the threaded arbor post. The 18 is the thread pitch — 18 threads per inch. UNF means Unified Fine thread. Milwaukee, DeWalt, Bosch, and Lenox all publish this spec on their arbor and cup product pages.
It's a de facto industry standard, not a coincidence. Grab an off-brand arbor in a pinch and a Milwaukee Hole Dozer cup will still thread on. The same logic drives blade sizing across brands — blade diameter compatibility works the same way across brands if you want the parallel.
What About Small Hole Saws?
Hole saws below 1-3/16″ in diameter use a smaller ½″–20 thread rather than the 5/8"-18 UNF standard.
If you're cutting small holes — knockout slugs, conduit entries, small access ports — double-check the arbor packaging before assuming 5/8"-18. The standard doesn't automatically hold below the diameter threshold.
2-in-1 Arbors
Some arbors handle two thread sizes via a built-in adapter, letting one shank cover both large and small hole saws. Milwaukee offers this through its QUIK-LOK™ adapters, which support both ½″–20 and 5/8″–18 threads; DeWalt does not offer an equivalent.
Milwaukee vs. DeWalt — Can You Mix Cups and Arbors?
Yes, at the thread level. No, for the quick-change feature. Those are two separate things.
Milwaukee's Hole Dozer quick-change arbors have a notch-lock slot on the arbor post. Hole Dozer cups with the matching notch drop in and lock without threading — fast, one-handed swap. Cups without that notch (DeWalt, Bosch, Lenox, or standard Milwaukee cups) thread on normally. The notch-lock just doesn't engage.
Not every Milwaukee Hole Dozer arbor in the lineup includes the quick-change notch — the lineup spans several configurations, so confirm the specific model includes the notch-lock feature before purchasing.
| Cup | Standard arbor (any brand) | Milwaukee quick-change arbor |
|---|---|---|
| Milwaukee Hole Dozer — notched cup | Threads on — no quick-change | Threads on + quick-change works |
| Milwaukee Hole Dozer — standard cup | Threads on | Threads on — no quick-change |
| DeWalt hole saw cup | Threads on | Threads on — no quick-change |
| Lenox / Bosch cup | Threads on | Threads on — no quick-change |
Milwaukee applies this same "backward-compatible, forward-optional" thinking to their battery ecosystem. If you want to see how that plays out elsewhere in their lineup, M12 and M18 batteries cross-compatibility is covered elsewhere.
Which Arbor Shank Do You Need?
3/8" Hex Shank — Standard Drills
Most cordless drills — M18 drill/drivers, 20V MAX drills, corded drills — take a 3/8" hex shank arbor. It's the default. If you're using a drill and haven't been specifically told otherwise, start here.
7/16" Hex Shank — Impact-Rated Arbors
Impact drivers need a 7/16" hex shank arbor rated for impact torque. The geometry and internal spec are both built to handle the rotational hammering an impact driver generates on a deep cut.
A standard 3/8" hex arbor will fit most impact driver chucks — but it's not rated for that load and can break. Physically fits ≠ rated for. For a full breakdown of hex shank sizing across driver types, shank sizing differs between drills and impact drivers covers it in detail.
| Tool type | Recommended arbor shank |
|---|---|
| Cordless drill / corded drill | 3/8" hex |
| Impact driver | 7/16" hex — impact-rated |
| Drill/driver combo | 3/8" hex; upgrade to impact-rated if running in impact mode |
The Pilot Drill — Size, Replacement, and Why It Wanders
Most arbors include a 1/4″ pilot drill that centers the hole saw before the cup bites — confirmed at that diameter for both Milwaukee and DeWalt, though Milwaukee lists the spec explicitly on the arbor product page while DeWalt does not.
The pilot takes more abuse than most people realize — it's first contact on every cut. When it starts to wander (the hole saw drifts at the start instead of biting clean), the tip is usually dull or bent. Overheating on deep cuts in metal is the other dead giveaway.
Replacement pilots are standard 1/4" bits, sold separately. Tool Army doesn't currently carry them, but any hardware store stocks them, and both Milwaukee and DeWalt sell OEM replacements through their accessory lines.
FAQ
Are hole saw arbors universal?
At the thread level, yes — for hole saws above roughly 1¾" in diameter. The 5/8"-18 UNF standard is shared by Milwaukee, DeWalt, Bosch, Lenox, and most major brands. The exception is Milwaukee's quick-change system, which requires a notched Hole Dozer cup to use the notch-lock feature. Any other cup threads on normally.
Can I use a Milwaukee hole saw with a DeWalt arbor?
Yes. Milwaukee Hole Dozer cups and DeWalt arbors both use the 5/8"-18 UNF thread. You lose the quick-change function, but the cup threads on and cuts normally.
What size arbor do I need for a hole saw?
For hole saws roughly 1¾" and larger: a 5/8"-18 UNF arbor. For smaller saws, the thread steps down to 1/2″ × 20.
What is a quick-change hole saw arbor?
An arbor with a notch-lock slot that lets you swap hole saw cups without threading them on — slide in, lock, cut. Milwaukee's Hole Dozer system is the most common quick-change setup in the M18 world. Cups from other brands thread on but don't engage the quick-change mechanism.
Can I use a hole saw arbor in an impact driver?
Only with an impact-rated arbor — typically a 7/16" hex shank built for impact torque. A standard 3/8" hex arbor fits most impact driver chucks but isn't rated for impact loads and can break on heavy cuts.
What size is the pilot drill in a hole saw arbor?
Most standard arbors include a 1/4″ pilot drill — the same size on both Milwaukee and DeWalt. Replace the pilot when it starts to wander on starting — dull or bent tip is the usual cause.
If you're running Milwaukee M18 or DeWalt 20V tools, browse the accessories built for your platform: Milwaukee accessories and DeWalt accessories. Both collections cover chargers, inverters, and driver accessories — the stuff that makes your existing tools work harder.