DeWalt 6 in. 18 TPI Straight Back Bi-Metal Reciprocating Blade (2 Pk)

What I put these blades through

I spend a lot of time with a recip saw in hand, cutting conduit, unistrut, stubborn fasteners, and the occasional section of pipe when a grinder isn’t practical. I ran these 6-inch, 18 TPI DeWalt metal-cutting blades through several weeks of jobsite tasks and shop tests: EMT conduit (1/2" and 3/4"), galvanized pipe up to 1", light and medium gauge steel angle, sheet metal, aluminum channel, and a handful of nails and screws during light demo. I also pushed them into a few tougher cuts—stainless trim and some hardened bolts—just to see where the limits are.

Build and design

The blades use a bi-metal construction with a straight-back profile and a 3/4-inch width. That recipe is pretty standard for a general-purpose metal blade, but a few design choices stand out:

• The tooth geometry does a good job clearing chips. On thin and medium steel, I noticed less “loading up” and a smoother feed than cheaper straight-cut teeth.
• The aggressive shank (tang) angle translates to reliable tooth engagement as you roll the saw shoe into the material. It helps the teeth bite quickly without skating.
• The anti-stick coating isn’t just a cosmetic touch. On aluminum and galvanized stock, it kept buildup to a minimum and reduced heat discoloration.
• Being bi-metal, the body flexes without snapping easily, and the teeth resist rounding better than bargain blades.

At 6 inches, these are compact and controlled. If you need deep reach or flush-cut versatility, you’ll want 9-inch versions, but the shorter length reduces deflection and vibration.

Cutting performance

Thin and medium steel

On 1/16" to 1/8" material, the 18 TPI profile is right in the sweet spot. The cut starts without much chatter and holds a straight line if you keep the shoe planted. I consistently got fast, predictable cuts on:

• EMT conduit and handrail tubing
• Sheet steel and HVAC plenums (though for very thin sheet, a 24 TPI will leave a cleaner edge)
• Slotted strut and light angle iron

Where some blades bog once chips build up, these keep clearing. Heat was manageable—most of my cuts could be made gloveless on the offcut within seconds, which tells me friction was under control.

Fasteners and demolition

Reciprocating blades live and die by how they handle the unpredictable cuts: nails, screws, and mixed-material demolition. These blades will slice framing nails, deck screws, and most general fasteners cleanly, provided you keep the saw square and avoid side loading. The 6-inch length is helpful in tight stud bays. However, if the fastener is truly buried and you’re prying and twisting at the same time, any 0.035"-ish bi-metal blade is at risk. For heavy demo through nail-riddled lumber, a thicker demolition blade with fewer teeth (or carbide tooth) is a better match.

Stainless and hardened stock

You can make your way through stainless trim and some automotive hardware with patience and lube, but this isn’t the ideal blade for hardened material. I got through a couple of stubborn bolts, though the cut rate dropped and heat rose quickly. That’s expected with 18 TPI bi-metal. If you routinely cut Grade 8 bolts, cast fasteners, or thick structural steel, step up to a carbide-tooth metal blade or go down in TPI for mass removal.

Durability and blade life

Blade life depends heavily on technique, material, and saw setup, but these held up well. Across a workday’s worth of conduit, strut, and pipe, I didn’t round the teeth prematurely, and the body tolerated accidental bends without cracking. I did intentionally kink one on a bound cut to see if it would recover; it straightened and kept working.

A couple of notes that helped extend life:

• Keep the shoe firmly against the workpiece to reduce vibration.
• Use variable speed—full trigger isn’t always faster. On thin steel, a slightly lower speed reduces chatter and tooth wear.
• A dab of cutting fluid on stainless or thick steel makes a noticeable difference.

Expect a markedly longer life than no-name blades and older budget bi-metal options. The manufacturer claims up to 50% longer life over a prior generation; I can’t quantify it precisely, but the wear pattern and edge retention tracked with what I consider a “premium” bi-metal experience.

Control, vibration, and cut quality

The straight-back design is predictable. It tracks well without wanting to wander, especially on flat stock and tubing. I ran my saw with orbital action off for metal, and the blades delivered clean, burr-minimal edges on 1/16" to 1/8" steel. On aluminum, the anti-stick coating helped maintain a smooth feed rate and avoided the gummy buildup that plagues uncoated teeth.

Noise and vibration are typical for this class—no glaring resonance or harmonic chatter beyond what you’d expect. The 3/4" width stabilizes the cut without feeling sluggish.

Fit, length, and versatility

At 6 inches, you’ve got enough stroke for most shop and field cuts while keeping control tight. The compact length is also kinder to the blade when you accidentally pinch the kerf; there’s less unsupported blade to buckle. If you’re making plunge cuts behind trim or need to reach deep past obstructions, keep a longer blade in the kit.

I would categorize these as “general metal” rather than “multi-material.” Yes, they’ll cut wood in a pinch, but the high TPI will slow you down and heat the blade. Use a wood demo blade for lumber.

Tips to get the best results

• Match TPI to thickness. For sheet metal under 1/16", grab a finer tooth count (20–24 TPI). For thicker mild steel, 14 TPI or carbide is faster.
• Turn off orbital action for metal cutting and let the blade do the work.
• Start each cut with a slow trigger pull to avoid skating, then ramp up.
• Keep at least two to three teeth in the cut; if it’s chattering on thin stock, tilt the blade slightly to engage more teeth.
• Use cutting fluid on stainless and thicker sections to reduce heat and extend life.
• Avoid side loading. If the kerf binds, pause and reposition rather than muscling through.

Value and alternatives

This two-pack sits in a sweet spot for price and performance. You can find cheaper blades, but they typically fold quickly on steel and round over after a handful of cuts. On the other end, carbide-tooth blades last dramatically longer in heavy steel and hardened fasteners, but they cost considerably more and are overkill for everyday thin-gauge metal.

If your work skews toward:

• Thin sheet and conduit: These 18 TPI blades are a practical, economical choice.
• Heavy demolition with nails: Choose a thicker, lower-TPI demolition blade.
• Hardened fasteners or frequent stainless: Go carbide-tooth; you’ll make up the cost in time saved.

As a consumable, these blades aren’t covered by a warranty, which is typical. They’re made in the USA with global materials.

Limitations

• Not the fastest choice for thick steel or hardened bolts.
• The 6-inch length limits reach for flush cuts or deep pockets.
• Bi-metal bodies can kink if you twist in a bind; use care in demolition scenarios.
• For ultra-thin sheet, a finer TPI will leave a cleaner edge.

None of these are dealbreakers given the intended use, but they’re worth noting to pick the right blade for the task.

Recommendation

I recommend these 6-inch, 18 TPI DeWalt metal-cutting blades for general metal work where control, predictable cut quality, and solid durability matter. They shine on conduit, strut, pipe, and light to medium steel, with a coating that keeps friction down and a tooth design that clears chips effectively. If your day is mostly thin- to mid-gauge steel with the occasional fastener, they’re a dependable, cost-effective staple.

If you regularly cut hardened bolts, thick structural steel, or do heavy nail-embedded demolition, look to a carbide-tooth or thicker demolition blade and/or a different TPI. But for the bread-and-butter metal cuts many of us make week in and week out, these blades hit the mark and hold it.