Jigsaw Blade Types Explained: T-Shank, U-Shank, and What Cuts What

T-Shank vs. U-Shank

T-shank blades have a tang shaped like the letter T that clicks into the blade clamp without tools. One push of the blade release lever, slide the blade in, and the clamp locks it in place. Every modern jigsaw manufactured in the last 15 to 20 years uses the T-shank system. Bosch developed the design, and it became the industry standard because it is faster and more secure than the older alternative.

U-shank blades have a half-moon cutout in the tang and require a setscrew or Allen wrench to lock them in place. U-shank is the older standard from the 1970s through the early 2000s. Blades are still available at most hardware stores, but the selection shrinks every year as manufacturers focus their production on T-shank. If you are buying new blades, check your jigsaw's clamp mechanism first.

If your jigsaw takes T-shank, buy only T-shank blades. They seat more firmly in the clamp, which reduces vibration and blade wander during the cut. If you have an older jigsaw with a U-shank clamp, you can still find U-shank blades from Bosch, DeWalt, and generic brands. But if you are buying a new jigsaw, the T-shank compatibility is universal and blade availability is not a concern. See our saw category page for jigsaw recommendations.

Wood Blades

For general wood cutting, a 6 TPI (teeth per inch) blade cuts fast through dimensional lumber, plywood, and sheathing. The aggressive tooth spacing removes material quickly, but the cuts are rough. Expect visible tooth marks and some splintering on the exit side. This is the blade for framing, demolition, and rough carpentry where cut quality is secondary to speed.

Fine wood blades at 10 to 12 TPI produce smoother cuts in hardwood, cabinet-grade plywood, and furniture parts. The trade-off is always speed versus cut quality. A 10 TPI blade cuts about 40% slower than a 6 TPI blade in the same material, but the edge it leaves needs little or no sanding. For visible edges on a bookshelf or cabinet, the time savings on post-cut cleanup more than compensate for the slower blade.

Reverse-tooth blades flip the equation on splintering. Standard blades have teeth that point upward, cutting on the upstroke. This pulls splinters out of the top surface of the workpiece. A reverse-tooth blade has teeth that point downward, pushing splinters back into the top surface and keeping it clean. The bottom side splinters instead, but that side is typically hidden.

Use reverse-tooth blades when the visible side faces up: laminate countertops, pre-finished plywood, veneered panels. For standard construction plywood where both faces are rough, a regular up-cutting blade is faster and the splintering does not matter.

Scroll Blades

Scroll blades are narrower than standard blades, typically 1/8-inch wide compared to the 5/16-inch width of a standard wood blade. The narrow profile lets them navigate tighter curves without the blade binding or the cut wandering. A standard-width blade handles curves down to about a 1-inch radius comfortably. A scroll blade handles curves down to 3/8-inch radius, which opens up decorative cutouts, lettering, and pattern work.

The trade-off with scroll blades is stability on straight cuts. The narrow body flexes more than a standard blade, so long straight cuts tend to drift or angle slightly. Some jigsaws have an orbital action setting that pushes the blade forward on the upstroke for faster cutting. Turn orbital action off when using scroll blades. The forward push on a narrow blade causes excessive flex and produces a wavy cut.

For projects that mix tight curves with straight sections, keep both blade types on hand and swap as the cut demands. The tool-free T-shank change takes about three seconds, so switching mid-project is practical.

Metal Blades

Metal-cutting jigsaw blades run 14 to 24 TPI and are constructed differently from wood blades. Most are bi-metal, with HSS (high-speed steel) teeth welded to a flexible carbon steel body. The HSS teeth stay sharp against metal, while the flexible body absorbs vibration. Some economy blades are all-HSS, which works but breaks more easily because the entire blade is rigid.

For sheet metal up to 1/8-inch thick, 18 to 24 TPI makes clean cuts without snagging or grabbing. The fine tooth spacing keeps multiple teeth in the cut at all times, which prevents the blade from catching on thin material and pulling it upward. For thicker metal (1/8 to 3/8 inch), 14 TPI cuts faster but leaves a rougher edge that may need filing.

Speed matters with metal. Reduce the jigsaw to medium or low speed when cutting metal. Full speed overheats both the blade and the workpiece, shortening blade life and discoloring the cut edge. A drop of cutting oil or wax on the blade every few inches reduces friction, extends blade life, and produces a cleaner edge. This is especially true for aluminum and stainless steel, which tend to gum up the teeth at high temperatures.

Specialty Blades

Carbide-grit blades cut cement board, fiberglass, and ceramic tile. They have no teeth in the traditional sense. A carbide coating on the edge grinds through abrasive materials that destroy standard toothed blades in seconds. Expect to pay $6 to $10 per blade, but they last through multiple cement board cuts where a toothed blade would not survive one.

Laminate blades are fine-toothed (12+ TPI) with a progressive tooth set specifically designed to minimize chipping on the melamine surface of laminate countertops and flooring. They cost $4 to $6 per blade and save the time of sanding or filing chipped edges after the cut. For a kitchen countertop cutout, a laminate blade is the difference between a clean edge and one that needs filler.

Flush-cut blades extend past the front of the jigsaw shoe, allowing you to cut right up to a perpendicular surface. They are useful for cutting flooring against a wall, trimming baseboard in place, or removing material flush to an adjacent surface. The overhang is typically 1/2 to 3/4 inch past the shoe edge.

Bosch, DeWalt, Diablo, and Lenox all produce specialty blades in T-shank format. Buying a variety pack ($12 to $20 for 10 to 15 blades) covers most situations and costs less per blade than buying singles.

Frequently Asked Questions

Why does my jigsaw cut crooked?

Three common causes. First, a dull or bent blade deflects under load. Replace it. Second, too much orbital action for the material. Reduce orbital action or turn it off for fine cuts and metal. Third, pushing the saw too fast so the thin blade flexes sideways. Let the blade cut at its own pace. If you force the feed rate, the blade bends and the cut wanders off the line.

Can a jigsaw cut a 2x4?

Yes, with a 6 TPI wood blade and full orbital action. It is slower than a circular saw or reciprocating saw, but it works. The maximum cutting depth of most jigsaws is 2-1/2 to 3-1/2 inches, so a 2x4 (1-1/2 inches actual thickness) is well within range. A 4x4 (3-1/2 inches actual) sits at the upper limit and requires a longer blade.

How do I reduce splintering on plywood?

Four strategies, in order of effectiveness. Use a reverse-tooth blade or a fine-tooth blade at 10+ TPI. Apply masking tape over the cut line before marking it. Cut with the good face down if using a standard up-cutting blade, since the bottom surface is the clean side on a conventional blade. Reduce orbital action to zero for the cleanest possible edge.

How many blades should I keep on hand?

At minimum: a pack of 6 TPI wood blades for general purpose work, a pack of 10 TPI fine wood blades for finish cuts, and a few 18 TPI metal blades. That covers 90% of jigsaw work. Add scroll blades and reverse-tooth blades as specific projects demand them. A $15 variety pack from Bosch or DeWalt covers the basics and fits in a drawer.

Related Reading

• Reciprocating Saw Blade Guide
• What Is TPI?
• What Is Orbital Action?
• Browse All Saws