The DEWALT DCS491B 20V MAX 18 Gauge Swivel Head Metal Shear is a cordless metal shear built for cutting sheet metal and ductwork with better control in tight spaces. This is a metal shear designed for sheet metal cutting, duct fabrication, and HVAC field work. Model Number: DCS491B. If you need a portable shear that can move around installed work instead of fighting a cord, this one is aimed right at that job.

On the numbers that matter, this tool cuts up to 18 gauge mild steel and 20 gauge stainless steel, with a 0 to 2,300 strokes per minute range for controlled cutting speed. DEWALT also uses a 7/32 inch strip cutting design that continuously curls waste away from the cut path. In plain terms, that helps keep the line visible and reduces the tendency for scrap to bunch up in front of the tool while you work through long cuts.

The biggest selling point here is the 360 degree tool-free swivel head. That is not just a spec sheet extra. When you're trimming spiral duct, making openings in installed sheet metal, or working in a mechanical room with limited space, being able to rotate the head without breaking out tools makes the cut easier to approach from a comfortable angle. You spend less time twisting your wrist or repositioning your body just to keep the tool lined up.

Because this is a cordless shear on the DEWALT 20V MAX platform, it is better suited to punch-list work, overhead cutting, and jobsite movement than a corded shop tool. You can carry it to the work instead of dragging extension cords across a slab or through finished space. That makes a difference for HVAC installers, sheet metal mechanics, remodelers, and general contractors who need to make quick, clean cuts on site rather than back at the bench.

DEWALT also includes an LED work light, which is one of those small features that matters more in the field than it does on paper. Mechanical rooms, basements, plenums, and unfinished interiors are not always well lit. A built-in light helps you track your line and the edge of the material when conditions are less than ideal.

At roughly 4.15 lbs, the tool stays manageable for repeated use, especially when you're following curved cuts or working on vertical material. The listed minimum cutting radius of 5.5 inches gives you a good idea of where it fits best: long runs, cutouts, and moderate curves rather than ultra-tight decorative detail work. This is a practical jobsite shear, not a specialty bench tool.

This is sold as a tool only configuration, so no battery or charger is included. That makes the most sense for users already on the DEWALT 20V MAX battery system who want to add a dedicated sheet metal cutting tool without buying duplicate power packs. If you already run DEWALT cordless tools, that lowers the cost of getting into the platform for HVAC and metal cutting tasks.

Who should buy it? The best fit is the user who regularly cuts duct, sheet metal, and light-gauge steel on site and wants cleaner control than a grinder or cutoff wheel for this kind of work. If your day involves fabrication adjustments, vent runs, cut-ins, or trimming installed metal, the DEWALT DCS491B 20V MAX 18 Gauge Swivel Head Metal Shear makes a strong case because it is purpose-built for that work, easy to maneuver, and fast enough to keep the job moving.

DEWALT DCS491B Metal Shear That Actually Makes Field Cuts Easier

The DEWALT DCS491B 20V MAX 18 Gauge Swivel Head Metal Shear is the kind of specialty cordless tool that pays off fast if you cut sheet metal more than once in a while.

• Who it's for: HVAC installers, sheet metal mechanics, and contractors who need to cut duct or light-gauge steel on site without dragging out a corded setup.
• Why it stands out: The swivel head is the real value here. It makes awkward cuts around duct and installed work a lot more manageable, and the strip-cutting action helps keep the path clear.
• Worth knowing: This is a bare tool, so plan on supplying your own DEWALT 20V MAX battery and charger. It is best for sheet metal work, not for material beyond its rated gauge capacities.

• What material thickness can this shear handle? It is rated for up to 18 gauge mild steel and 20 gauge stainless steel.
• Is this a cordless tool? Yes. It is a cordless battery-powered shear on the DEWALT 20V MAX platform.
• Does the cutting head rotate? Yes. The head swivels 360 degrees and adjusts without tools for better access and working position.
• What is the minimum cutting radius? The listed minimum cutting radius is 5.5 inches.