DeWalt OSC 1-1/4 in. Metal Cutting Blade (3 PK)

I reached for DeWalt’s 1-1/4-in metal blade on a week of mixed punch-list work: trimming copper stubs, shaving off proud fasteners, opening up a small plaster-and-lath cavity, and cutting a couple bolts where a reciprocating saw wouldn’t fit. It’s sold as a metal-cutting accessory for oscillating tools, but as with all OMT blades, the real story is about matching expectations to the task—and using the right technique to keep heat under control.

Setup and fitment

The Universal Fitment connection clicked into several bodies I tried—DeWalt, Milwaukee, and Makita—without fuss. It’s genuinely tool-free and solid. The tapered profile is a plus. I could sneak into tight corners, feather a plunge, and get a clean sightline for flush cuts along trim and subflooring. If you swap blades often across brands, the fitment alone makes life easier.

Build and design

This blade is bi-metal with a high-speed steel (HSS) cutting edge and a heat-dissipating coating. In the hand, it’s stiffer than a wood blade but not as thick as carbide-tooth oscillating blades. The kerf is fine, and the tooth pattern is shallow and closely spaced—exactly what you want for thin metals and controlled cuts, not for hogging through dense stock. The coating helps resist discoloration initially, but prolonged heat builds quickly on any oscillating blade; managing that is part of the job.

Cutting performance in metal

• Copper and aluminum: On soft, nonferrous metals—3/4-in copper pipe and thin aluminum trim—it performed well. Low speed, light pressure, and a modest drip of cutting oil gave me smooth, controllable cuts. The edge stayed sharp long enough to complete several trims without complaint.

• Thin steel stock: On sheet metal and thin EMT conduit (thin-wall), the blade works, but you have to go slow, keep the tool speed moderate, and let the teeth do the work. Pushing harder just makes heat. With oil and a gentle rocking motion, I got usable results, but it’s not fast.

• Fasteners (screws, nails, bolts): This is where expectations need to be realistic. Oscillating blades excel at access and control, not outright speed or longevity in hardened steel. Cutting a rusted deck screw flush, the blade managed a few without drama, then dulled noticeably. Roofing nails were similar—fine for a handful, but you’ll feel the edge go off sooner than you’d like. I had one stainless bolt to handle in a tight space, and with oil, patience, low oscillation speed, and minimal pressure, I got through it cleanly. The blade emerged scuffed but intact. Still, hardened drywall screws and multiple treated-deck fasteners are tough on this HSS edge; the teeth will round off quickly if you lean on it or run it hot.

• Mixed-material demo: Oscillating blades often end up in plaster, lath, and old work where grit destroys wood blades. Here the HSS edge helped. I opened a small section of plaster and cut through the underlying wood lath without exploding the plaster keys. It wasn’t fast, but the edge held better than a typical wood blade in gritty material.

Technique matters more than marketing

A few habits made a big difference in my results:
- Keep speed moderate. High OPM skyrockets heat.
- Use cutting oil on steel and stainless. Even a drop reduces friction and tooth wear.
- Feather the cut. Let the blade self-feed; force just polishes teeth.
- Rock the blade slightly to expose fresh teeth and shed chips.
- Take cooling breaks. Ten seconds off can save a blade.
- Avoid side-loading. Oscillating blades don’t like twisting.

With those habits, the blade stays productive for light metal work. Ignore them, and you’ll see tooth loss in minutes.

Durability and blade life

It’s a three-pack, and I treated it as such: one blade for soft metals and plumbing chores, one for occasional fasteners and flush cuts, and one as a sacrificial backup. On soft metals, life is respectable. On mild steel and nails, life drops off fast if you overheat it. Compared with carbide-tooth oscillating blades I use for heavy nail cutting, this HSS edge simply isn’t in the same league for longevity on hardened fasteners. That’s not a knock on the blade so much as a reminder of class and intent.

One note on heat: if you see smoke or paint scorching, you’ve already shortened the blade’s life. Dial back speed, add oil, or switch tools.

Access and control

Where this DeWalt blade earns its keep is access. I could make clean flush cuts along finished surfaces without the kickback or overcut risk of a grinder or recip saw. That’s the reason to keep a metal-cutting oscillating blade in the kit: precision and safety in tight quarters. The tapered shape helped me start plunges without skittering, and the 1-1/4-in width is a sweet spot for visibility and stability.

Comparisons and use cases

• Use this blade if:

  • You need controlled, precise cuts in soft metals—copper, aluminum, thin-gauge steel—especially in finished spaces.
  • You occasionally cut a few nails or screws during trim or cabinet adjustments, and access is the priority.
  • You’re opening plaster and lath and want an edge that handles grit better than a wood blade.

• Consider a carbide-tooth oscillating blade if:

  • You routinely cut hardened drywall screws, decking screws, or many nails.
  • You need substantially longer life in steel.

• Consider a recip saw or grinder if:

  • Speed matters more than precision.
  • You’re cutting thicker steel stock or making repeated fastener cuts. A reciprocating saw with a quality bi-metal or carbide blade will simply outlast and outpace an oscillating blade on heavy metal.

Value

As a three-pack, the cost per blade matters. Performance-wise, you’re buying control and compatibility. You’re not buying a miracle worker for hardened steel. There’s no limited warranty on these, which is typical for consumable blades, so value hinges on whether your tasks align with the blade’s strengths. If most of your “metal” is copper, aluminum, or occasional mild steel in a tight space, the three-pack makes sense. If you’re routinely chewing through nails and screws, you’ll burn through these quickly and would be better served with carbide.

Pros

• Universal fitment locks in securely across major brands
• Tapered profile improves visibility and access for flush cuts
• Clean, controllable performance on copper, aluminum, and thin steel
• Coating and HSS edge handle gritty plaster better than wood blades
• Three-pack is convenient for assigning blades to different tasks

Cons

• Tooth life drops fast on hardened screws and multiple nail cuts
• Heat builds quickly at high OPM; requires oil and patience
• Not the best choice for thicker or repeated steel cuts
• No limited warranty (typical for consumables, but worth noting)

Recommendation

I recommend this DeWalt metal blade for light-duty metal work where access and control matter more than raw speed: trimming copper and aluminum, occasional mild steel cuts, and clean flush work in finished spaces. It also serves as a capable “grit-friendly” option for plaster and lath where wood blades fail quickly. I do not recommend it for frequent cutting of hardened screws, roofing nails, or repeated steel work—upgrade to a carbide-tooth oscillating blade or move to a recip saw or grinder for those tasks.

Used within its lane, it’s a reliable, precise accessory to keep in your oscillating tool kit. Used as a heavy-metal problem solver, it will frustrate you. Matching the blade to the job—and pacing the cut—makes all the difference.