DeWalt 4" 6 TPI U-Shank Fast Rough Wood Cutting Cobalt Steel Jig Saw Blade

Why I reached for this blade

I keep a mix of coarse and fine jigsaw blades in the shop, and when I’m roughing in openings or trimming down construction lumber, I want a blade that eats wood without complaining. This DeWalt U‑shank wood blade fits that role: a short, stout 4-inch profile, a coarse tooth pattern geared for speed, and a bi‑metal construction meant to hold up when the cut gets hot or a stray fastener sneaks into the line. It’s not a finish blade, and it doesn’t pretend to be. It’s a get-it-done blade for framing, demolition-adjacent tasks, and aggressive cuts in sheet goods.

Setup and compatibility

This blade uses a U‑shank, which is worth calling out. If you’re running an older Black & Decker, Skil, or a “universal shank” jigsaw, it should slot in with no fuss. In my older Craftsman saw, it locked up firmly with the set-screw clamp and tracked true. If you’ve moved to a modern pro jigsaw with a T‑shank quick-change system, this isn’t the blade for you unless you keep a U‑shank saw around. There are adapters out there, but they’re clunky; I’d stick with native T‑shank blades on those platforms.

The blade length is 4 inches, which translates to an effective cutting depth of roughly 2 to 2-1/2 inches in real use, depending on your saw’s shoe and stroke. That’s plenty for 2x lumber as long as you’re not beveling deep or trying to get fancy with curves.

Cutting performance

The tooth pattern on the blade I tested is coarse—think fast rip more than fine crosscut. In 2x SPF studs, it’s quick. With my jigsaw set to a high orbital action and medium-to-high speed, I could zip through a 2x4 in seconds. The deeper gullets do their job; chips clear well, and the cut doesn’t bog unless you bury the blade in sappy knots without easing the feed.

Plywood and OSB were similar stories: fast, reasonably controllable cuts with predictable tear-out on the exit face. This isn’t a reverse-tooth or high-TPI blade, so backer boards or painter’s tape help if you care about the surface. On 3/4-inch CDX, the blade tracked straight with minor deflection when I pushed too hard near the edge of the sheet. Dialing back the orbital and letting the blade do the work fixed it.

MDF is a mixed bag for any coarse blade. The DeWalt drives through it quickly, but the dust is fine and the edges chip easily. Slowing the stroke and reducing orbital motion improved edge quality at the cost of speed. For shelf-grade MDF cuts, I’d go with a higher TPI blade. For rough cutouts or scribing cabinet backs, this blade is fine.

Curves are manageable within reason. The blade’s short length helps reduce wandering, but the coarse teeth and aggressive bite mean tight radiuses require patience and pilot holes. For scroll work, this isn’t the pick.

Accuracy and cut quality

There’s always a trade-off between speed and finish. This blade leans heavily toward speed. It leaves a serviceable, shop-rough edge that’s ideal for framing, HVAC cutouts, window rough-ins, and work where the edge will get covered or cleaned up later with a plane or sander. With steady feed and a slower orbital setting, the surface finish improves, but it never crosses into “cabinet clean.” That’s consistent with the design.

Plunge cuts are straightforward. The blade’s stiffness and coarse tooth form make it easy to toe the shoe and drop into plywood or drywall without skating. Just score your line and commit; the cobalt-bi‑metal body resists the heat that can blunt cheaper high carbon blades in repeated plunge work.

Durability and heat resistance

The cobalt‑alloy bi‑metal construction is the quiet advantage here. In extended runs through 2x and OSB, the teeth stayed sharp and resisted the blueing you sometimes see on high-carbon steel after a long cut, especially with orbital action cranked up. I hit a drywall screw hidden in an older subfloor and expected to see a couple teeth folded over; instead, I got barely a nick and kept cutting. It’s not a metal-cutting blade, but it shrugs off incidental contact much better than single‑alloy HCS wood blades.

After several hours of mixed cuts, the edge was still chewing confidently. At that point, I’d swap to a fresh blade for clean tracking on straighter cuts, but for demolition, rough carpentry, and template trimming where precision is less critical, this one kept going. That longer edge life is where the value shows.

Vibration and control

One surprise: the blade runs relatively smooth for such a coarse profile. Precision-ground teeth and even set help. In my saw, vibration was moderate, about what I expect from a fast-cutting wood blade. A lighter-duty jigsaw will transmit more chatter; keeping the shoe firmly planted and letting the orbital do the clearing keeps cuts under control.

Blade wander is minimal when the saw’s shoe is flat to the work. In deep cuts—think ripping down the narrow dimension of a 2x—pushing too hard can still cause deflection. The fix is simple: slow your feed, reduce orbital, and clear chips. The deeper gullets help, but they’re not magic if your cutline is full of wet pitch.

Where it shines

• Fast rough cuts in construction lumber, OSB, and plywood
• Plunge cuts for electrical boxes, vents, and window rough openings
• Tasks where speed and endurance matter more than a polished edge
• Situations with the occasional hidden fastener—bi‑metal buys you forgiveness

Where it struggles

• Clean, splinter-free edges in veneered plywood and MDF
• Tight curves and scroll-like work
• Users with T‑shank-only jigsaws—this is for U‑shank clamps

Tips for best results

• Use orbital action for speed, then dial it back for cleaner edges or tighter curves.
• For veneer ply, tape the cutline and cut from the show side supported by a sacrificial backer.
• Let the blade set the pace. If you feel the saw bouncing or see the blade wandering, ease the feed and clear chips.
• Keep a fine-tooth blade on hand for finishing passes; this DeWalt gets you there quickly, then swap if the edge will be seen.

A note on tooth count

DeWalt catalogs this family as a fast, rough-cut wood blade, and the one I used exhibits a coarse tooth profile consistent with that role. If you’re buying, check the packaging for the TPI—some listings show different counts under similar part numbers. For rough carpentry, the coarse version is the right choice; fine TPI variants belong to a different task.

Value

The longevity advantage matters. Cheaper high carbon blades cut fast when fresh, then dull quickly, especially under heat or when you accidentally nick hardware. This bi‑metal blade keeps working longer, which means fewer swaps and less frustration mid-cut. If you’re in a U‑shank ecosystem, it’s an easy upgrade over bargain-bin wood blades.

The bottom line

This DeWalt U‑shank wood blade is a straightforward, capable workhorse for fast cuts in wood and sheet goods. It prioritizes speed and durability over finish quality, and it delivers exactly that. The cobalt‑alloy bi‑metal body outlasts basic HCS blades, the deeper gullets clear chips effectively, and the precision-ground teeth keep the cut controlled for a coarse profile. It won’t replace a fine-tooth blade for furniture-grade edges, and it won’t fit newer T‑shank-only jigsaws. But if you’re running a U‑shank saw and you spend time in framing lumber, subfloors, or rough carpentry, it’s a dependable blade to keep in the kit.

Recommendation: I recommend this blade for anyone using a U‑shank jigsaw who needs fast, rough cuts in wood and sheet goods with better durability than standard high carbon steel. It’s not a finish solution and it’s not for T‑shank saws, but within its lane, it’s reliable, long-lasting, and efficient.