DeWalt Heavy Metal Bi-Metal Reciprocating Saw Blades

A metal-cutting staple that rewards good technique

I put the DeWalt bi-metal recip blades through a month of mixed metal work—demo cuts, shop fabrication, and a little automotive tinkering—to see where they shine and where they fall short. Short version: they’re dependable workhorse blades for ferrous metals, especially mild steel and cast materials, with better-than-average cut control for a 6-inch format. Push them into thick stainless or thin sheet without adjusting your approach, though, and you’ll burn time and blades.

Build and design

These are 6-inch, 14 TPI bi-metal blades with a notably tall profile. The extra height stiffens the blade and pays dividends in straighter cuts, less flex, and fewer “banana” cuts when you’re deep in angle iron. The bi-metal body offers the usual recipe: a spring-steel backer for flexibility and a hardened cutting edge for durability. DeWalt’s tooth geometry is tuned for chip evacuation; it’s not a wild hook angle, but it moves swarf out of the kerf more cleanly than generic 14 TPI blades I’ve used. They’re made in the U.S.A. with global materials, and the fit and finish—straightness, tooth set consistency, and paint quality—were excellent out of the package.

Cutting performance

I tested across common shop and jobsite metals using a 10-amp orbital reciprocating saw and a variable-speed 12-volt compact saw.

• 1/4 in x 1-1/2 in mild-steel angle: With a few drops of cutting fluid and a moderate stroke rate, I averaged clean cuts in roughly 20–25 seconds. The tall profile helped me keep a square line without riding a guide, and the chips cleared well with minimal clogging.

• 1/2 in EMT and rigid conduit: No drama. The 14 TPI kept the start smooth and reduced snagging on the exit. If you’re cautious about grabby starts, a slight backstroke to create a small notch, then a slower feed, made it nearly foolproof.

• 5/8 in zinc-plated threaded rod (AISI 1018): Fast and predictable. I made about 18 cuts on one blade before noticing appreciable slowdown.

• Cast iron hub-and-spoke register: Slower by nature, but the blade tracked straight and didn’t chatter. I prefer a lower SPM and steady pressure here, and the teeth held up fine.

• 304 stainless exhaust pipe (2-1/2 in OD): This is where the limitations show. Stainless work-hardens quickly and sheds heat poorly, and a 14 TPI bi-metal blade needs patience. With cutting fluid, reduced SPM, and a gentle feed, I got through one cut, but I retired the blade afterward—it was noticeably dulled. A second cut cost me another blade. If stainless is your daily driver, a carbide-tooth recip blade is the right tool.

On thin sheet and soft nonferrous metals, your mileage depends on technique. The 14 TPI will happily eat thicker aluminum extrusions, but on 0.040–0.063 aluminum sheet or thin stainless sheet, it tends to snag unless you back off the feed and increase stroke speed. An 18–24 TPI blade is better for thin stock.

Durability and blade life

Against mild steel, the edge life is genuinely good for a bi-metal. I tracked one blade through a small demo day: eight cuts in 1/4-inch angle, two lengths of 1-inch black pipe, and a handful of threaded rod cuts. It still had usable bite afterward and didn’t lose teeth. Heat control matters a lot; when I cut dry at full speed, I could smell the edge going. With fluid and a moderate stroke rate, life roughly doubled.

The tall profile reduces flex fatigue. I had zero snapped blades and fewer “set wobbles” where a blade gets kinked and starts wandering. The edge dulls predictably rather than catastrophically shedding teeth, which is exactly what you want from bi-metal.

Accuracy and control

If you struggle to keep recip cuts square in heavier stock, the extra stiffness here helps. I could keep a cut line within a blade’s width over 2–3 inches of depth without a shoe fence. In quarter-inch angle, wandering was minimal once the initial notch was established. Vibration was average to slightly better than average—helped by chip evacuation that reduces the “hammering” you get with packed teeth.

Starting cuts was smooth. The toothform doesn’t aggressively pull into the work, so you don’t get that violent bite that can kick the shoe off the surface. That also means your cut speed isn’t artificially fast at the beginning only to slow down as the blade loads up. The feed rate stayed consistent.

Best uses and limitations

Where these blades shine:
- Mild steel structural shapes, pipe, and rod
- Ductile iron and cast iron with a patient feed rate
- Copper and thicker aluminum extrusions (with attention to chip load)
- General demolition where you want straighter cuts from a stiff 6-inch blade

Where they struggle:
- Thick stainless and hardened alloys; they’ll cut, but you’ll pay in blade life
- Very thin sheet metal; a higher TPI is a better choice to prevent snagging
- Deep reach cuts requiring an 8 or 9-inch blade

Tips to get the most out of them

• Slow down for harder metals. Lower SPM and a steady, moderate feed preserves the edge.
• Use cutting fluid on stainless and thicker stock. A light oil makes a big difference.
• Let the blade do the work. Forcing the cut overheats the teeth and shortens life.
• Notch first. A short back-and-forth pull to create a starter notch improves tracking.
• Match TPI to thickness. Keep a 18–24 TPI option on hand for thin sheet to avoid tearing.

Value

In a five-pack, the cost-per-cut felt competitive, especially considering the cut control and straightness I got from the taller profile. I ran fewer “do-over” cuts compared to generic blades, which is time saved. If you rarely touch stainless, these make economic sense as your primary metal blade. If stainless is common, you’ll go further on a cost-per-cut basis with carbide-tooth blades despite the higher upfront price.

What I’d change

I’d love to see this exact tall-profile body offered in a mixed pack with a higher TPI option for sheet metal and an 8-inch variant for reach. The 6-inch length is the most versatile general-purpose size, but metal work often benefits from having a longer blade when you need a deeper stroke to avoid binding in larger pipe. A printed wear indicator on the blade body would also be welcome for gauging life at a glance.

The bottom line

These DeWalt bi-metal blades are a solid, predictable choice for everyday metal cutting in mild steel, cast materials, and general demolition. The tall profile improves tracking and cut quality, the toothform clears chips effectively, and edge life is good as long as you manage heat and feed. They’re manufactured in the U.S.A. with global materials, and the consistency from blade to blade in the pack I used was excellent.

Recommendation: I recommend these if your work centers on mild steel, conduit, and occasional cast iron, and you value straight cuts from a stiffer 6-inch blade. If you frequently cut stainless or hardened alloys, skip bi-metal and invest in carbide-tooth blades for better life and fewer blade changes. For the right materials and with good technique, these are dependable, no-drama performers that earn a place in the kit.