How Does a Jigsaw Work? – Definition & How to Use it

How Does A Jigsaw Work
Photo: Bosch

If you are on a tight budget and don’t have access to a workshop with plenty of woodworking tools, a jigsaw can help you to get a lot done.

It is very versatile because it can be used to cut different materials and can make different types of cuts.

What is a Jigsaw?

A jigsaw is a powered saw that runs a straight blade in an up and down motion, which is similar to the movement of a sewing machine’s needle.

This reciprocating movement creates the cuts either in the downstroke or upstroke, depending on the direction that teeth face on the blade.

The result is a very versatile tool that is ideal for cutting curves and circles in wood or metal sheets.

It may not be as easy to use as a bandsaw, but it has the benefit of being easily portable, which allows you to carry it to any work site.

How Does a Jigsaw Work?

Just like any other saw, a jigsaw is run by a motor. Well, you might be wondering how the blade runs in reciprocating movement and here’s how.

The motor rotates a set of eccentric gears that have off-center axes. These gears convert rotary motion into reciprocating motion and connect to the blade to move it up and down.

The saw’s cutting speed is controlled by adjusting the motor’s speed, which in turn speeds up or slows down the reciprocating movement.

That said, there are corded and cordless jigsaw types and each has its benefits.

Corded units are more powerful and provide consistent cutting power due to their unlimited energy source.

On the other hand, cordless jigsaws are the most portable and can be used even when the power is out.

How to Properly Use a Jigsaw?

How to Use a Jigsaw

1. Use the Correct Blade

When using a jigsaw, the first thing to do is to attach the ideal blade for the task at hand. Carbon steel blades are the best for cutting wood and PVC plastic pipes while bi-metal blades are ideal for cutting thin metal sheets.

You should also check the teeth density. Coarse blades with few teeth per inch are ideal for cutting thick wood but result in aggressive, rugged cuts.

On the other hand, fine blades with as much as 12 teeth per inch are suitable for thin pieces of wood such as plywood because they won’t shred the edges. For metal blades, this number can rise to 36 teeth per inch.

Read More: Types of Jigsaw Blade

2. Lay the workpiece

Clamp the workpiece and mark cut lines on the surface using a pencil.

If you need to make plunge cuts, it is recommended to drill the first hole if the material is hard or thick. Otherwise, you can use your jigsaw.

3. Adjust the shoe if required

Most jigsaws are equipped with an adjustable shoe that allows you to make bevel cuts.

Simply locate the adjustment screw, loosen it, adjust the shoe to the required angle then fasten the screw.

4. Run the Blade

Once everything is properly set up, align the saw with the cut line then run the blade at full speed before making contact.

If making a straight cut, make sure you use a guide rail to maintain high accuracy. If cutting very tight curves, ensure to make relief cuts to prevent the blade from binding. 

It is important to note that the shoe should be lying flush to the workpiece’s surface at all times. To achieve this, run the saw while pressing it down using both hands.

Safety Tip: While using a jigsaw, remember to cover your eyes, nose, and mouth using safety goggles and a dust mask respectively.

Also, if using a corded saw, always keep an eye on the cord to avoid tripping.

Jigsaw FAQs

1. Can I Use a Jigsaw Vertically?

Yes. A jigsaw can be used to cut vertically, but it is recommended to fit it with a flush-cut blade.

This is because as you get closer to the ground, the shoe will contact the floor first before the blade.

However, a flush-cut blade extends further outwards than the shoe to complete the cut.

2. Can a Jigsaw Cut Through a 2×4?

This is possible, but you need a powerful jigsaw and a long, stiff blade with few teeth per inch.

Also, a bi-metal blade should be used because the thickness makes it tough.

Most high carbon steel blades can only cut through 1.5 inches in softwood and 0.75 inches in hardwood.

3. How Thick of Wood can I Cut with a Jigsaw?

This usually depends on factors such as the power of the jigsaw, type, and length of the blade.

With all these factors being at the very best, you can cut up to a 3-inch thick stock.