DeWalt 1 in (25 mm) hole saw

Why I reached for this 1-inch hole saw

There are a handful of sizes I keep within easy reach, and 1 inch (25 mm) is one of them—ideal for conduit, grommets, cable pass‑throughs, and plumbing vents. I put this 1-inch hole saw through a mix of jobsite and shop tasks to see how it holds up across wood, metal, and plastic. The short version: it’s a straightforward, workmanlike cutter with a few smart details that matter in daily use.

Design and build

This is a bi‑metal cup with a high‑speed steel cutting edge, bonded to a flexible steel body. That combination is the standard for general‑purpose hole saws because it balances tooth hardness with body resilience. The cup depth is a true 1.75 inches (44 mm), which is enough to swallow a 2x board’s actual 1.5-inch thickness in a single pass. That sounds minor until you’re halfway through a sill plate and trying to back out a plugged saw—extra depth makes the cut cleaner and less fussy.

Two details stand out:
- The tooth geometry is clearly designed for chip evacuation. The set and rake aren’t overly aggressive, which helps the saw track accurately without chattering.
- A large continuous slot runs along the sidewall. That uninterrupted opening isn’t just a finger hold; it gives you leverage to pop out plugs instead of prying in three directions and chewing up the kerf.

The cup is finished in high‑visibility yellow and the size marking is legible. There’s no case in the package and no arbor included—it’s just the saw. That’s fine by me; most of us already have arbors on hand. It accepts a standard pilot with a 1/4-inch bit, and the minimum drill chuck spec is 1/4 inch, so it’s compatible with compact drivers as well as full-size drills.

Made in the USA with global materials is the label, and the fit and finish align with that: no sloppy welds, true threads, and a concentric cut in practice.

Setup and compatibility

I ran it on two arbors: a quick‑change style with a 3/8-inch shank for general work and a solid‑shank arbor for low‑speed metal drilling. The pilot bit seated squarely, and the cup spun true with negligible runout. If you’re drilling metal, make sure the pilot’s edge is fresh—at this diameter, a dull pilot will wander and turn the first contact into a skid mark.

A note on speed:
- Wood: 400–800 RPM worked well depending on species; slower for hardwoods.
- PVC and acrylic: 200–400 RPM with a light feed to prevent melting.
- Mild steel: 150–250 RPM with cutting fluid.

Staying conservative on speed preserves the tooth edge and keeps heat under control.

In wood: clean, controlled, and deep enough

I started with construction lumber: SPF 2x4 and pressure‑treated 2x material. The deeper cup cleared the board in a single pass with room to spare, no need to flip the workpiece. Chip ejection was very good; the tooth form throws coarse chips rather than dust, and I didn’t need to feather the trigger to avoid clogging. In 3/4-inch oak plywood, the entry edge stayed crisp with minimal tear‑out. For cabinetry or exposed faces, a strip of painter’s tape and a backing board pegged the exit clean, but even without those, the kerf quality was respectable for a bi‑metal saw.

Tracking was excellent. The saw didn’t skate once the pilot bit started, and I didn’t feel the jack‑hammer effect that some coarser‑tooth cups produce when they catch alternating plies in plywood. Heat discoloration was mild after multiple holes; I let the saw spin free for a second to clear chips between cuts and it never cooked the paint.

In metal: predictable performance with proper technique

I tested on 18‑gauge mild steel electrical box covers and 1/8-inch flat stock. With cutting oil and a steady feed at around 200 RPM, the saw made clean, round holes without chipping teeth. On the thicker stock, I peck‑drilled: advance, back out to clear chips, repeat. The side slot earns its keep here—metal slugs can be stubborn, and that continuous opening lets you twist a flat screwdriver behind the slug and pop it out without gouging the tooth line.

Burrs on the exit side were typical for a bi‑metal saw—plan on a quick pass with a deburring tool or file. I wouldn’t pick this for stainless plate on a regular basis; it can do the job slowly with fluid and patience, but you’ll shorten the tool’s life. For stainless or repeated metal‑only work, a carbide hole saw would be my first choice. For mild steel, electrical knockouts, and aluminum, this bi‑metal cup is right in its element.

In plastics: low heat, clean edges

PVC, ABS, and acrylic all cut cleanly at lower RPMs. The tooth geometry is fine enough to avoid chunking brittle plastics, and I didn’t see melting or welding of chips in the kerf as long as I kept the speed down and paused to clear swarf. If you need a pristine edge in acrylic, a quick chamfer after the cut does the trick.

Plug ejection and slot design

Plug ejection is where small design choices either help or frustrate you. The continuous slot is wide and accessible, and it’s offset enough to give you purchase even on thin material. In softwood, most plugs dropped out with a tap; in wet pressure‑treated lumber and in plywood, I used a flat screwdriver and the slot to lever out the plug in one motion. Compared to side holes, the continuous slot reduces the time you spend picking out stuck biscuits.

Durability and wear

After a day of mixed cuts—dozens in SPF and plywood, a handful in mild steel, and several in PVC—the teeth still felt sharp to the fingernail and showed no chipped tips. The paint wore where expected near the gullets, but heat tint was minimal. That tracks with the claim of improved chip evacuation: cooler chips mean longer life. As always, technique matters more than marketing—control speed, use fluid in metal, and don’t side‑load the cup.

Accuracy and finish

The saw cut true to size; a 1-inch hardwood dowel fit with a push and slight wiggle, which is what I expect from a bi‑metal kerf. For press‑fit bushings, you’ll need a reamer or a different approach; for cable pass‑throughs, grommets, and conduit fittings, the diameter is on spec. Entry tear‑out in wood was minor, exit tear‑out depends on backing. In metal, plan for a deburr pass.

Limitations and quirks

• No arbor in the package. That’s common, but worth noting if you’re buying your first hole saw.
• Not the right tool for masonry, tile, or frequent stainless steel work.
• Like all bi‑metal cups, it will leave burrs in sheet metal that need cleanup.
• There’s no case, and the bright finish scuffs quickly—not a performance issue, but if you like pristine‑looking tools, it’ll show use.

None of these are deal‑breakers; they’re just realities of the category.

Tips for best results

• Let the pilot bit finish its work before feeding the teeth into the material; it reduces walking and chatter.
• In thick stock, peck the cut—advance, back out, clear chips. It keeps temperatures down and extends life.
• Use a backing board on veneered plywood or finished faces to prevent blow‑out.
• For plastics, lower RPM and a light feed prevent melting.
• In metal, cutting fluid isn’t optional if you care about tooth life.

Who it’s for

Electricians, plumbers, cabinet installers, and woodworkers who regularly need clean, accurate 1-inch holes in wood, plastics, and mild steel will get exactly what they expect from this saw. DIYers with a single project will appreciate that it works with common arbors and hand drills and doesn’t require specialized technique.

Verdict

This 1-inch hole saw hits the right notes: a durable bi‑metal edge, a cup deep enough for 2‑by lumber in a single pass, and a genuinely useful continuous slot that makes plug removal quick. It tracks straight, cuts cleanly across wood, metal, and plastic with appropriate technique, and holds up well over a full day’s mixed use. It’s not a specialty cutter, and it doesn’t pretend to be—it’s a reliable, general‑purpose hole saw that does the job without drama.

Recommendation: I recommend it. If you need a dependable 1-inch hole saw for wood, mild steel, and plastics, this one offers solid cut quality, efficient chip clearing, and a depth that simplifies through‑cuts in framing. The lack of an included arbor and case is normal for this category, and the performance more than justifies its spot in the kit.