DeWalt General Purpose 3-Sided Oscillating Blade

Why this three-sided blade earns a spot in my oscillating kit

My first outing with the DeWalt 3-sided oscillating blade was a tidy little remodel: adding a pair of outlets in a finished room without turning the place into a dust storm. A multi-tool shines at that kind of surgical work, and this blade in particular makes it almost too easy to drop in rectangular openings with clean, square corners. After several weeks of drywall, trim, and a few nail-riddled framing jobs, I’ve got a clear sense of where this blade excels and where it doesn’t.

Setup and compatibility

Mounting is straightforward. The Universal Fitment back engages cleanly with tool-free clamps on modern oscillating tools, and it also works fine on bolt-style holders (you’ll just spend an extra minute with a wrench). On OIS-compatible tools in the shop—DeWalt and Milwaukee—it locked in without fuss and stayed put. If you’re running a Starlock-only tool, you’ll either need an adapter or a Starlock version; that’s not a knock on the blade so much as a note on the landscape of oscillating interfaces.

The blade’s 2-1/8 in cutting width is more than a spec-sheet number—it aligns really well with single-gang box layouts. You can mark your opening, sink the blade along your lines, and complete the rectangle with minimal overcutting. The three-sided profile is the right shape for this: straight edges that let you plunge each side, meet neatly in the corners, and avoid the arc marks circular blades leave behind.

Drywall performance: fast, square, and tidy

In drywall, speed and control matter more than brute force. The chamfered cutting edge on this blade helps with both. It seems to shed gypsum dust better than flat-ground profiles I’ve used, which keeps the cutline visible and reduces the tendency to chatter as the gullets clog. Plunge starts are predictable—find your line, feather the trigger, and the blade walks into the wall without skating.

Cut quality is clean enough that you can set a box without chasing fuzzy edges with a rasp. If you’ve ever used a typical straight plunge blade and ended up with ragged corners, the three-sided layout here is a meaningful upgrade. It’s not a dustless solution (no oscillating blade is), but chip evacuation is good, and the sheet face doesn’t tear out as long as you let the blade do the work.

Wood with nails: confidence with caveats

DeWalt calls this a general-purpose, nail-tolerant blade, and it lives up to that billing. In softwood framing, it chews through the occasional embedded finish nail or stray brad without losing its temper. I purposely ran it into a few old, dull box nails during a baseboard demo—cuts stayed controlled and the teeth didn’t round off after the first strike, which is exactly what you hope for from a bi-metal blade with a high-speed steel edge.

A few realistic limits show up with tougher hardware. Hardened screws, structural fasteners, and modern ring-shank nails will shorten the party. You can still complete the cut, but the blade heats up faster and you’ll notice progress slow after repeated strikes. That’s normal for HSS; if you’re going to be swimming in fasteners all day, a carbide-toothed accessory is the right play. For the mixed bag of renovation work—old trim, occasional nail hits, exploratory cuts in questionable substrates—this blade hits a sweet spot between speed, durability, and cost.

Light metal: better than expected, within reason

Oscillating blades aren’t my first choice for long metal cuts, but they’re great for controlled trimming where a shear or cutoff wheel can’t reach. I used this blade to trim the thin steel skin on a steel-clad exterior door and to notch a couple of HVAC boots. It handled both without chipping paint or burning the edges, provided I kept the stroke moving and let the teeth clear. Important qualifier: we’re talking sheet metal, not plate. The blade will take you through the skins and hems you see in residential doors and ducts; it’s not for slicing angle iron or hardened hardware.

Heat is your enemy in metal, so let the blade cool between passes. The teeth held up well across several light-metal chores, and I didn’t notice any tooth loss—just normal polishing on the cutting edge.

Control and visibility

One reason I kept reaching for this blade over standard plunge blades is line-of-sight. The three-sided profile and cutting width give you a stable, flat edge to register against a straightedge or a box template. You can nudge the blade to sneak up on a scribed line without the “hook and jump” you sometimes get from narrower profiles. The corners it leaves are crisp enough that plastic electrical boxes drop in cleanly without carving a relief.

On softer materials, I got the best results running the tool at a medium-high speed and using a slow, rocking plunge. That keeps the gullets from packing up and makes the chamfered edge actually do what it’s designed to do: pull dust out of the cut and prevent wandering.

Durability and value

Bi-metal blades are a balancing act: you trade the brute survivability of carbide for a smoother, faster cut and a lower price. This one sits in the durable end of the bi-metal spectrum. Across a few dozen drywall cutouts, several trim notches, and a handful of nail encounters, it stayed sharp enough to keep working cleanly. It did eventually show the typical HSS dulling after repeated nail strikes, but it didn’t shed teeth or warp.

From a value standpoint, it makes sense as a “daily driver” blade for remodeling and service work. I reserve the pricier carbide blades for heavy demo or when I know I’ll be swimming in fasteners. For everything else, this blade covers a lot of ground efficiently.

Where it shines, where it doesn’t

Strengths:
- Accurate plunge cuts and square corners in drywall
- Nail-tolerant edge that survives incidental strikes
- Solid control and visibility along layout lines
- Easy mounting on most OIS-style tools with tool-free clamps

Trade-offs:
- Not the best choice for frequent contact with hardened screws or dense fasteners
- Width is ideal for single-gang work, but can feel bulky in very tight recesses
- Starlock-only tools will require an adapter or a different blade pattern

Tips for best results

• Let the blade do the work. A light feed pressure keeps it on line and extends edge life.
• Use a shallow rocking motion on plunges to help the chamfer evacuate dust.
• If you expect to hit a lot of metal, reduce speed a notch and take breaks to manage heat.
• Keep a scribe or box template handy; the blade tracks well along a scored line.

The bottom line

As an all-purpose cutter for drywall, wood, and the occasional light metal, the DeWalt 3-sided blade earns its keep. It’s especially good at one of the most common multi-tool tasks—electrical box cutouts—where its width, profile, and chip control add up to clean results with minimal fuss. The bi-metal, HSS-edged construction gives you a real buffer against incidental nails without jumping straight to carbide pricing, and the universal mount works seamlessly on the majority of tools you’ll see on a jobsite.

I recommend this blade. If you’re a remodeler, electrician, or homeowner who leans on an oscillating tool for clean, controlled cutouts and careful trim modifications, it offers a reliable mix of accuracy, durability, and convenience. Save your carbide blades for heavy demo; keep this one loaded for everything else.