Bi-Metal vs Carbide Hole Saws for Stainless (2026)
Bi-metal hole saws cut mild steel. Carbide-tooth hole saws are what you buy when the work is stainless, harder alloy, or anything that sands a bi-metal tooth flat. The arbor and pilot bit decide whether the cup you already own will run. This page is that decision. Brand-vs-brand bi-metal kits are here: Hole Dozer vs Lenox vs Diablo.
No hands-on scoring. Guidance follows published tooth type and the thread standards shops already use. Confirm fit on the arbor you own before you order a cup. This page does not cover SDS-plus, SDS-Max, or concrete core bits.
Pick the tooth first
| Work | Tooth | Why |
|---|---|---|
| Mild steel, aluminum, wood, plastic | Bi-metal | Cheaper cups, more diameters, fine if you use oil and low RPM |
| Stainless sheet and tube | Carbide tooth | Bi-metal overheats and dulls; carbide keeps an edge in stainless |
| Cast iron, cement board, abrasive stock | Carbide tooth | Abrasive material eats bi-metal |
| One hole in thin stainless, then back to mild steel | Bi-metal, with oil, if you accept a shorter life | A carbide cup is wasted money for a single light cut |
Carbide teeth are brazed on. They cut harder material and they chip if you side-load the cup or start crooked. Bi-metal teeth are tougher against a bad start and useless once stainless work-hardens under a dull edge.
Slow RPM, cutting fluid, and a firm pilot matter more than the logo. A carbide saw run dry at high speed still dies.
Arbors, pilot bits, and mandrels
The cup does not chuck into the drill. An arbor (mandrel) does.
Two thread sizes cover almost every trade hole saw you will see in a US shop:
- Small cups, roughly 9/16 in to 1-3/16 in: 3/8”-24 thread.
- Larger cups, roughly 1-1/4 in and up: 1/2”-20 thread.
Hole Dozer, Lenox, and Diablo bi-metal cups in those ranges use those threads. A “universal” arbor is universal only for the thread it is cut for. A 1/2-20 arbor will not run a 3/8-24 cup. Read the cup, not the brand story.
Pilot bit. The arbor carries a replaceable twist bit that centers the cut. When it dulls, replace the pilot. Do not keep leaning on a dull pilot and blaming the cup. Match the pilot shank to the arbor (the set-screw or the quick-change collar has to clamp it). Brand-matched pilots are the safe buy. A random bit that “almost fits” walks.
Quick-change vs fixed. Quick-change arbors swap cups without wrenches. Useful if you change diameter all day. A fixed arbor is fine if you run one size. Either way the thread on the cup has to match.
What does not interchange
- SDS-plus and SDS-Max shanks are for rotary hammers and masonry bits. They are not hole-saw arbors.
- Concrete core bits use their own barrels and often a different drive. Do not adapt one onto a bi-metal cup and call it a metal saw.
- A mandrel sold for one brand’s quick-change collar can refuse another brand’s collar even when the cup thread is the same. If the listing does not name your cup system, assume it does not fit.
How to buy without duplicating the other page
If the job is mild steel and you are choosing among Hole Dozer, Lenox, and Diablo, use the bi-metal comparison. Buy carbide here only if stainless or abrasive material is the actual work.
A carbide kit with two or three diameters plus a 1/2-20 arbor covers most stainless tube and sheet. Add a 3/8-24 arbor only if you need the small cups. Oil is not optional on stainless.
Check before you pay
- Tooth type on the manufacturer page: bi-metal or carbide. Marketplace titles mix them.
- Thread: 3/8-24 or 1/2-20, and whether an arbor is in the box.
- Pilot bit included, and whether replacements are sold for that arbor.
- Max material thickness the maker lists. A cup rated for thin sheet is the wrong tool in 1/2 in plate.
- Current price and seller. These are commodity cutters. Stock changes.
Related
- Hole Dozer vs Lenox vs Diablo
- Shop drills — rotary drill with a side handle, not an impact driver.