What Size Jigsaw Blade Do You Need for Your Project?

What "blade size" actually means

When people ask what size jigsaw blade they need, they usually mean one of three things: length, tooth count or shank. Each one answers a different question, and you need all three to be right.

Length tells you how thick a board the blade can cut through. TPI tells you how rough or smooth the cut will be. The shank is the part that locks into your saw, and if it does not match, the blade will not fit at all.

Most modern jigsaws take T-shank blades, and every blade on our best jigsaw blades comparison uses that shank. Older saws may need U-shank blades, so check your manual or the old blade before you buy.

How long are jigsaw blades?

Jigsaw blades are fairly short compared with blades for other saws. Among the blades we compare, the shortest is 2.625 inches and the longest is 4 inches. Several well-known blades sit in between, at 3.25 and about 3.6 inches.

Keep in mind that overall length is not the same as usable cutting length. The shank and the untoothed end take up part of it. For example, the Bosch T101A is listed at 4 inches overall with a 2 3/4 inch working length. That working length is the number that limits how thick a board you can cut.

Match blade length to the thickness of your material

A good rule of thumb is that the blade should stick out past the bottom of the material at the end of each stroke. A blade that is too short will bottom out in thick stock, bind and may snap. A blade that is far longer than you need can flex and wander, which makes a straight line harder to hold.

That is why a shorter blade can be a smart pick for thin sheet work. The 2.625 inch Bosch T102BF is the shortest blade we list, and it is made for straight cuts in thin acrylic. Longer blades give you reach, but shorter ones give you more control.

Some listings also state a thickness range, and that is more reliable than guessing. The JMD reverse-tooth blades are listed for material from 3/16 inch to 1-1/4 inches thick. The Bosch Plexiglas blades are listed for 5/64 inch to 3/4 inch thick. If your material falls outside the stated range, look for a different blade.

Choose teeth per inch for the finish you want

TPI is the second half of the size question. Fewer, larger teeth remove material quickly but leave a rougher edge. More, smaller teeth cut slower and leave a cleaner edge.

Here is how the blades we compare line up:

• 6 TPI: fast cuts in wood, such as the DEWALT DW3750-5 with deep gullets for clearing waste.
• 10 TPI: general wood and panel work, including the reverse-tooth blades from JMD and DEWALT.
• 13 to 14 TPI: plastics and laminates, where a finer tooth reduces chipping and melting.
• 18 to 20 TPI: fine and curved cuts, such as the 20 TPI Bosch blades for scroll cuts in laminate flooring.

Pick the blade for your project

Once you know the thickness and the finish you want, the choice gets simple. For rough framing lumber, go with a long blade and a low TPI. For a countertop or shelf where the top face shows, a reverse-tooth blade cuts on the downstroke and pushes splinters into the board instead of tearing the top surface.

For laminate flooring and melamine, a carbide blade at 14 TPI is a common match, since carbide holds up against hard, brittle sheets. For plastics such as acrylic, a bi-metal or high speed steel blade in the 13 to 14 TPI range suits the job. You can compare these options side by side on our jigsaw blade comparison page.

If you do many different jobs, a mixed set saves a trip to the store. The DEWALT DW3741C is a 10-piece set with 6, 10 and 18 TPI blades for wood and metal, and it comes with a case. The JMD set has 30 blades, the biggest pack count we list.

Can you get longer jigsaw blades?

Yes, some makers sell longer blades for thick stock such as deep timber or stacked layers. The blades we compare top out at 4 inches, so we cannot give you specifications for anything longer.

Before you buy a longer blade, check your saw's manual. Your saw's stroke length, power and guide roller are designed for a typical blade. A very long blade can flex, wander off the line and put extra strain on the saw. For thick material, cut slowly and let the blade do the work, or mark both faces and cut from each side.

Safety and a quick checklist

Always unplug a corded saw or remove the battery from a cordless one before you change a blade. Blades get hot during use, so let them cool before you touch them. Wear safety glasses, because broken blade pieces and chips can fly. Wear hearing protection for longer jobs, and clamp your work so it cannot jump.

Before you buy, run through this list:

• Confirm the shank type, usually T-shank.
• Measure the thickness of your material.
• Pick a length that clears the underside of the cut.
• Choose TPI for the material and the finish you want.
• Decide whether a reverse-tooth blade is needed to protect the top face.

Frequently asked questions

Do jigsaw blades come in different lengths?

Yes. The blades we compare range from 2.625 inches to 4 inches, and some makers sell others outside that range.

Does a longer blade cut faster?

Not by itself. Speed depends mostly on TPI and tooth design. A coarse 6 TPI blade removes material faster than a fine 20 TPI blade of the same length.

Can I use a T-shank blade in an older saw?

Maybe. Some T-shank blades fit most U-shank saws, as the Diablo listings say, but check your manual or the shank on your current blade first.

Are jigsaw blades interchangeable between brands?

Often yes, if the shank type matches. A T-shank blade from one brand usually fits a T-shank saw from another, but confirm in your saw's manual.

When should I replace a blade?

Replace it when cuts slow down, the blade burns or melts the material, or the edge turns rough. Carbide blades usually last longer in hard, brittle sheets.