DeWalt 9-Piece 2X Electrician's Bi-Metal Holesaw Kit

I put this DeWalt kit to work on a week of electrical rough-in: boring through SPF studs and plates, popping holes in EMT straps and light-gauge panel covers, and tackling a handful of PVC and plywood penetrations. The takeaway is straightforward: the cups themselves are durable, predictable cutters with genuinely useful deep-cut bodies and smart ejection slots; the quick-change mandrels speed things up; the pilot bits are the weak link and worth upgrading on day one.

What’s in the box and why it matters

This is a nine-piece electrician-focused set with hole saws in 7/8 in, 1-1/8 in, 1-3/8 in, 1-3/4 in, 2 in, and 2-1/2 in plus both small and large quick-change mandrels and a replacement arbor. The size selection makes sense for electrical rough-ins—running cable bundles through plates, boring framework for conduit, and opening knockouts in wood-backed panels. If you’re looking for a general carpentry kit, you’ll notice gaps: there’s no 2-1/8 in cup for locksets, no 1-1/2 in, and nothing above 2-1/2 in for recessed lights. For what it’s intended to do, the range lands well.

Everything rides in a compact case. It’s a typical blow-molded setup: secure enough that saws don’t tumble out in transit, but you’ll still hear some rattle. The cups nest cleanly and the sizes are etched deep enough to stay legible after a few cleanings.

Build quality and design

The cups are bi-metal with a tooth alloy that includes cobalt (DeWalt cites up to 8.75%). Tooth height is noticeably taller than older-generation cups I’ve used, and the shells have hardened backing plates to keep threads from stripping. The deep-cut bodies are worth calling out—there’s enough depth to clear a standard 2-by in a single pass without babying the drill.

The quick-change system includes both small and large mandrels. Swap-over is fast: retract the collar, drop the cup, click on the next one. On my sample, the large mandrel had a touch of runout, but nothing that affected performance in wood, and only a minor annoyance in thin metal where wobble can create chatter. The pins and threads are robust; I didn’t see the usual galling that cheaper cups suffer after a few changes.

Cutting performance in wood

In SPF studs and top plates, this kit does what it claims. The deep-cut body clears a 2-by in one pass, usually with one planned back-out to dump chips on the larger sizes. The tooth geometry is on the smoother side—less grabby than some aggressively raked cups. Feed rate felt consistent across sizes. The 2-1/2 in cup chewed through treated lumber without burning; I kept the drill around medium speed and let the teeth do the work.

Plug ejection is better than average. The staggered slots give you multiple angles to pry. A few plugs practically fell out when I reversed the drill and tapped the rim. Dense, resinous studs still needed a screwdriver jab, but I didn’t have the usual wrestling match that comes with single-slot designs.

Cutting performance in metal and plastics

For light-gauge metals, the cups hold their own. I cut several holes in 18- and 16-gauge mild steel covers and brackets using cutting fluid and slow RPM. The 1-1/8 in and 1-3/8 in sizes tracked true and produced clean edges with minimal burr. The 2 in cup will do 16 gauge if you manage heat and let chips clear; push it and you’ll see bluing at the gullets. I wouldn’t choose these for repeated 1/8 in plate—possible with patience, but not the right tool for that grind.

PVC conduit and ABS cut cleanly, no melting at a medium-low speed. Plywood behaved like the SPF studs: smooth, controllable, and predictable.

The pilot bit problem

The pilot setup is the soft spot. The included bits are serviceable in wood for a little while, but mine dulled quickly in sheet metal and showed visible wear after a handful of holes. I also had to retighten the pilot bit set screw more often than I’d like. Swapping to a higher-quality 135-degree split-point cobalt pilot bit made an immediate difference in tracking and longevity, especially in metal. It also helps reduce walking on painted surfaces.

If you buy this kit, plan on replacing the pilot bit early and keep a spare in the case.

Speed, heat, and technique

A few practical notes from use:
- Use a drill with a side handle and a working clutch. Big cups can grab.
- In wood, moderate speed with steady feed prevents burning and extends tooth life.
- In steel, slow the RPM way down, add cutting fluid, and don’t force the cut. Heat is the enemy.
- Back the saw out periodically to clear chips—especially on the 2 in and 2-1/2 in cups in deep lumber.

Follow those habits and the cups stay sharp appreciably longer. After a week’s mixed use, the teeth on the smaller sizes still felt crisp; the 2-1/2 in showed light discoloration but kept cutting cleanly.

Mandrels and changeover

The small and large quick-change mandrels cover the full size range of the cups, and the system is genuinely handy when you’re alternating between, say, 1-3/8 in and 2 in holes on consecutive studs. The locking mechanism never let a cup slip, and the hardened backing plate appears to do its job—no chewed threads, no binding after repeated swaps.

If you’re sensitive to wobble, note that quick-change systems tend to introduce a hair more runout than threaded-only setups. On this kit, it was minor and manageable.

Durability and value

Bi-metal cups live or die by heat and operator technique. Within that context, these are on the durable end for a mid-tier electrician’s set. The tooth height and cobalt content seem to pay off: edge chipping was minimal, and I didn’t experience tooth loss. The hardened backing plate is a quiet win—it protects the arbor threads and threads in the cup from strip-outs that can ruin a day on site.

Given the included sizes, two mandrels, and replacement arbor, the kit covers most electrical rough-in needs without a lot of extra fluff. The 30-day money back guarantee is standard fare; there’s no extended warranty on consumables like hole saws, and that’s fine—this category typically doesn’t carry long guarantees.

What could be better

• Pilot bits: too soft and too short-lived in metal. Replace immediately.
• Size selection for generalists: missing a few common carpentry sizes (not a knock if you accept it’s an electrician’s kit).
• Minor mandrel runout: acceptable, but worth noting if you do a lot of thin sheet work.

Who it’s for

• Electricians roughing in wood framing who need clean, single-pass holes through 2-by material.
• DIYers tackling electrical projects who prefer a compact, trade-focused set over a giant assortment.
• Anyone who values quick-change mandrels for frequent size swaps.

Who should look elsewhere:
- Locksmiths or door installers needing 2-1/8 in and 1 in lockset sizes.
- HVAC and plumbing techs who need larger diameters or heavy-gauge metal specialization.
- Metal fabricators working primarily in thicker stock.

Bottom line and recommendation

The DeWalt kit is a solid, trade-focused set that cuts cleanly, goes through 2-by in one pass as advertised, and benefits from thoughtful features like staggered ejection slots, deeper cups, and hardened backing plates. The quick-change mandrels are convenient and robust. Its Achilles’ heel is the pilot bit quality; performance in metal improves dramatically with a better pilot, and even in wood you’ll notice the upgrade.

I recommend this kit for electricians and anyone doing electrical rough-in in wood framing who wants a reliable, compact set of bi-metal hole saws with deep-cut capability. Plan to replace the pilot bit immediately and mind your speeds in metal. With those caveats, it’s a dependable daily driver that balances speed, durability, and convenience without straying into gimmicks. If you need a more general-purpose assortment or plan to drill heavy-gauge steel regularly, there are better fits; otherwise, this kit earns a spot in the truck.