Jigsaw Blade Types, Teeth and Uses Explained

What a jigsaw blade is

A jigsaw blade is a thin, narrow strip of steel with teeth along one edge and a mounting shank at the top. The saw moves it up and down very quickly, and the teeth remove a small amount of material with each stroke. Because the blade is narrow, it can follow curves that a circular saw cannot.

Every blade has the same basic parts: the shank that locks into the saw, the body, the teeth and the gullets, which are the spaces between teeth that carry sawdust out of the cut. Small changes in each part make a blade better or worse for a given material.

Check the shank first

The shank decides whether a blade fits your saw at all. Most modern jigsaws take T-shank blades, and every blade on our spec sheet uses the T-shank. Older saws may need U-shank blades, so check your manual or the old blade before you buy. A wrong shank will not lock in.

Some listings, such as the Diablo blades, say their T-shank design fits all combo and most U-shank jigsaws. Treat that as a reason to confirm compatibility with your saw's manual, not as a guarantee.

Teeth per inch: fast versus fine

TPI is the number of teeth in one inch of blade. Fewer teeth are larger and cut fast but leave a rougher edge. More teeth are smaller and cut slower but leave a smoother edge. Coarse blades also have deeper gullets, which clear chips quickly in soft materials.

As a rule of thumb, pick the lowest TPI that still gives the finish you want. Thin or hard materials need more teeth in contact with the work, so a coarse blade can snag or chip them.

• Low TPI (about 6): framing lumber and other rough wood cuts where speed matters more than finish.
• Mid TPI (about 10 to 14): general wood, plywood, laminate and plastics.
• High TPI (about 18 to 20): fine scroll cuts and brittle or abrasive sheet materials such as laminate flooring.

Blade materials compared

Material controls how long a blade stays sharp and whether it can flex without snapping. Harder materials last longer in abrasive boards but can be more brittle. You can see these differences across the blades on our best jigsaw blades page.

Here is how the common materials line up, using the blades on our spec sheet as examples.

The two types: standard and reverse blades

Most jigsaw blades are standard blades. Their teeth point toward the shank and cut on the upstroke. This gives good control because the saw's base plate is pressed down against the work. The catch is that the teeth lift fibers as they exit, so the top face can splinter while the underside stays clean.

Reverse blades, also called down-cutting blades, have teeth that point the other way and cut on the downstroke. They push the fibers into the board instead of lifting them, which gives a cleaner top face. That makes them a good choice for countertops, shelving and any piece where the top surface shows.

The JMD T101BR set and the DEWALT DW3762-5 are both listed as reverse down-cut blades at 10 TPI. The DEWALT is made for laminate, and the JMD is listed for wood, plastic, laminate, OSB and particle board.

A third style also appears: bidirectional teeth. The Diablo carbide blade on our page is listed as bidirectional, with the aim of clean finishes on both the top and bottom.

What reverse blades are used for

Reverse blades suit work where one face matters most. Cutting a sink opening in a laminate countertop from above is a classic case, because any chipping would be on the visible surface. They are also useful for veneered plywood and prefinished panels when you can cut with the good side up.

There are trade-offs. A reverse blade tends to lift the saw's base slightly, so hold the saw firmly down on the work and keep a steady feed. Also remember that the underside of the cut may now be the rougher face, so mark and cut with that in mind.

How to match a blade to the job

Start with the material, then work through shank, TPI and cut direction. For example, plexiglass and acrylic need a blade that cuts cleanly without melting the plastic, so the blades on our page for that job are fine-toothed, such as the Diablo bi-metal 13 TPI and the Bosch T102BF at 2.625 in, the shortest on our sheet.

Follow these steps before you cut:

• Confirm your saw takes T-shank blades.
• Identify the material and its thickness.
• Choose a TPI that keeps several teeth in the work at all times.
• Decide whether the top or the bottom face needs the cleaner edge, and pick standard or reverse teeth to match.
• Pick a material, such as carbide for laminate flooring or bi-metal for mixed work.
• Decide on pack size. A starter set like the DEWALT DW3741C has 6, 10 and 18 TPI blades in 10 pieces, while the JMD pack has 30.

Safety when changing and using blades

Unplug a corded saw or remove the battery before you change a blade. Blades get hot during use, so let them cool before you touch them. Clamp the workpiece so it cannot vibrate or shift, and keep the cord and your free hand clear of the cutting line.

Wear safety glasses to protect against chips and broken blade fragments. Use hearing protection for longer sessions, and a dust mask when cutting laminate, MDF or particle board, which produce fine dust. A bent or dull blade can snap, so replace it rather than forcing it through the cut.

Frequently asked questions

What is a jigsaw blade made of?

Most are steel in some form: bi-metal, high speed steel or chrome-vanadium steel. Carbide-tipped blades add a harder cutting edge for abrasive materials.

Can I use a wood blade on plastic or metal?

It is better not to. A coarse wood blade can crack or melt plastic and will wear quickly in metal. Choose a finer blade made for the material.

Does a higher TPI always mean a better cut?

No. More teeth give a smoother edge but cut slower and can clog in thick, soft wood. Match the TPI to the material and thickness.

How long should a blade be?

The blade should be long enough to pass fully through the material and a little beyond. On our sheet, lengths run from 2.625 in to 4 in.

When should I replace a blade?

Replace it when cuts slow down, the edge burns or chips, or the blade drifts off the line. Bent or missing teeth are a clear sign to swap it out.