DeWalt 3" 14 TPI U-Shank Thick Metal Cutting Cobalt Steel Jig Saw Blade

Why I reached for this blade

Metal cuts with a jigsaw can be a mixed bag—too fine a tooth and you burn time (and the blade), too coarse and you chatter and chip teeth. I’ve been working through a run of small-shop tasks—trimming angle iron brackets, shortening threaded rod, and making a couple of interior cutouts in 1/8-inch steel plate—where dragging out the bandsaw or cutoff wheels felt like overkill. That’s where the DeWalt cobalt U‑shank jigsaw blade has been living in my kit: quick to install, surprisingly controlled in thicker metal, and tough enough to finish the cut without drama.

Design and build notes

A few design choices stand out:

• Curved tooth profile: The teeth have a subtle curve that softens entry and spreads the workload across more teeth. In practice, that means less snatching when you start a cut and fewer stripped teeth if your feed pressure wavers.
• Deep gullets: The chip pockets are generous. On mild steel, they actually clear swarf rather than compacting it, which helps the blade stay cooler and keeps the cut moving.
• Bi‑metal with cobalt: The cutting edge holds up under heat better than plain HCS. I saw the usual light temper coloring during long cuts, but tooth sharpness stayed serviceable rather than crumbling or rounding off quickly.
• Short, 3-inch length: That makes the blade inherently more rigid. It doesn’t wander as easily as longer blades when you’re steering around a radius or following a scribed line.

It’s a U‑shank, so compatibility is the key caveat. If your jigsaw accepts universal U‑shank blades, you’re set. If you’re on a strictly T‑shank saw (which is increasingly common), this one won’t lock in. No amount of praise can get around that limitation.

The two-pack is simple and practical. I burned one blade on purpose by pushing it hard, and the second confirmed the more realistic use-case performance I describe below.

Setup and best settings

I ran the blade in a variable-speed jigsaw with orbital action disabled. If your saw allows orbital stroke, keep it off for metal; it reduces chip load per tooth and keeps the cut smoother. My settings that worked best:

• Low to mid blade speed for ferrous metals; faster for aluminum
• Firm shoe pressure and two-hand control to prevent chatter
• A few drops of cutting fluid on the line every inch or two
• Work clamped tightly with a clear path for the blade and chips

With U‑shank clamps, getting the blade seated fully and square is worth an extra check; some older saws give a hair of slop if you rush the install.

Cutting performance

On 1/8-inch mild steel plate: The blade maintained a steady feed without squeal once I found the sweet spot on speed and pressure. The start of the cut was drama-free—no tooth grab that can skid you off your line. I could steer a 2–3-inch radius reliably, and straight cuts stayed within about a blade’s thickness of a scribed mark. Burr formation was moderate; a quick pass with a file or flap wheel cleaned the edge easily.

On 3/16-inch angle iron: Still very workable. The blade liked a touch more lubricant, and I reduced speed slightly to keep heat in check. It didn’t spring off the web-to-flange transition, which is where cheaper blades sometimes chip teeth. Expect a comfortable, controlled pace—not fast, but predictable.

On 1/4-inch flat bar: This is the upper limit I’d call efficient for a jigsaw, but the blade got it done. Feed pressure had to be patient and uniform; pushing hard only made heat and risked dulling. If you need to do many cuts at this thickness, a bandsaw or cutoff wheel wins on time. For a couple of pieces, this blade is a convenience hero.

On EMT and aluminum: The deep gullets help keep chips moving, but aluminum can load any tooth if you go too slow with no lube. A smear of wax or fluid kept things clean, and the edge finish was better than I expected. For EMT, the blade tracked nicely around the curve without biting or hopping.

Stainless steel: With a light touch and plenty of fluid, it will cut thin stainless sheet, but this is not a production stainless blade. Heat management becomes critical, and tooth life drops quickly if you push.

Control and accuracy

The shorter length pays off in guidance. I had minimal blade wander, even with grainy, mill-scale surfaces. Using the jigsaw’s guide roller close to the work helped, and I found the blade tolerant of small direction changes without facetting the cut. For internal cutouts in plate, a small pilot hole is the cleanest start—plunge starts are possible but harder on teeth with thicker stock.

Kerf is narrow enough to make small relief cuts and sneak up on a line without losing stiffness. I also noticed less vibration transmitted to the work than with some longer, coarser alternatives—partly the tooth geometry, partly the length.

Durability and heat resistance

With sensible technique—no orbital, controlled speed, consistent fluid—the blade’s cobalt edge holds its profile longer than standard bi‑metal I keep around for general purpose. After several feet of cutting mixed stock (mostly 1/8-inch steel, some thicker sections), the lead teeth were still cutting, not plowing. Abuse it with dry, high-speed runs and you can blue it and round the tips, as expected. The curved tooth layout seems to distribute load so the first few teeth aren’t the only ones doing the work.

One practical note: let the blade cool between long cuts. Heat cycling in metal work is half the battle for blade life.

What it’s not

• Not universal-fit: If you don’t have a U‑shank saw, this is an immediate non-starter.
• Not a production solution for heavy sections: Repeated cuts in 1/4-inch and beyond will be slow and shorten blade life. Right tool, right job applies.
• Not a finish blade: Edge quality is solid for metalwork, but if you need polished edges, plan on post-processing.

Value and warranty

The two-pack format and a straightforward 30‑day money‑back guarantee make this an easy add to a metalworking kit. Given the longevity I saw compared to non-cobalt bi‑metal options, the cost per cut is reasonable, especially if you’re using it as intended in thicker mild steel rather than abusing it at high speed.

Tips to get the most from it

• Disable orbital action; run a moderate speed for steel.
• Use cutting fluid. A few drops stretch blade life significantly.
• Clamp work securely and support close to the cut line to reduce chatter.
• Let the blade do the work. If chips turn blue or you see smoke, slow down.
• Clear chips periodically on long cuts; pause, let it cool, add fluid, continue.

The bottom line

I keep the DeWalt cobalt U‑shank jigsaw blade in my drawer for those “just a few cuts” moments in thicker metal where a grinder is messy and the bandsaw feels like too much setup. Its curved tooth design starts smoothly and resists chipping, the deep gullets keep the cut moving, and the cobalt bi‑metal edge stands up to the heat that metal cutting inevitably brings. It’s at its best on 1/8-inch to 3/16-inch mild steel, will manage occasional 1/4-inch work if you’re patient, and handles conduit and aluminum cleanly with a bit of lube. The main drawback is compatibility—T‑shank users will need a different blade—and the 3-inch length limits utility on very deep material.

Recommendation: I recommend this blade if you have a U‑shank jigsaw and need a dependable option for occasional to moderate cutting in thicker metal. It’s controlled, durable for its size, and predictable, which is exactly what I want when I’m choosing a jigsaw for metal work instead of a more dedicated cutting tool. If your saw only accepts T‑shank blades or you’re doing production-level metal cutting, look elsewhere; otherwise, this is a solid, workmanlike choice.