A jigsaw is a precision tool with a thin blade, which makes them ideal at cutting intricate designs on thin material.
If you ever had to cut a 2x4 piece of framing lumber with a jigsaw and thought to yourself... "there's no way", you might be surprised! There’s a way to do it – slowly, patiently, and with the right setup.
To cut 2x4 consistently with a jigsaw, you have to keep drift and flexing to a minimum. All too often, an inexperienced jigsaw user will make a cut that’s dead on straight on top, but beveled out and off the cutting line at the bottom.
To cut straight, perpendicular clean cuts through thick wood with a thick saw, you need to be in control of the blade at all times.
That means going for a more powerful jigsaw and stiffer blades. It also means that you have to spend a bit more time and attention as you let the blade do the work for you.
The Right Setup To Cut A 2x4 With A Jigsaw...
Blades: You will need a jigsaw blade that’s appropriate for cutting through thicker wood. As a general rule, the thicker the workpiece you need to cut, the lower the teeth per inch you need to go for.
I would recommend a tooth count (tpi) of 10 and lower for cutting through 2x4's.
Blade Stiffness: Jigsaw blades designed for thick lumber have low TPI and a wider kerf, which means rougher cut quality when you are done.
It also means that you have a thicker, stiffer blade that’s less prone to flexing or wandering, which is crucial if you are cutting through wood with prominent grain.
Blade Material: As for the jigsaw blade material, you will want one of the harder (and more expensive) types.
High carbon steel will dull relatively easily and can fade out in the middle of a deep and long cut. For cutting 2x4 wood with a jigsaw, you will want to stick to high-speed steel or better. I recommend the bi-metal blades for this.
Blade Length: You will also need to make sure that your blade is long enough to get the right depth of cut you need to make. It depends on the stroke length of your jigsaw, along with the length of the blade you are using.
TIP!
In general, you need to get a blade that is 1 inch longer or more than the workpiece you are cutting through. For a 2x4, that means getting a 2 1/2" blade (at the very minimum). A 3" blade usually works well, in my experience.
A Square: A speed square or combination square is crucial for marking lines and can act as a guide in some cases when cutting too. You will also need a square to check that your blades are perfectly perpendicular before you make the cut.
Finally, having a powerful jigsaw with a higher RPM (to handle the thicker stock) is an added bonus and most jigsaws made nowadays should be capable of meeting this requirement.
How to do Straight Cuts in 2x4 Lumber
Pick the right type and length of the blade for the type of wood you are working with. Before turning the tool on, check that the blade is perfectly perpendicular to the shoe using a speed square (or similar).
Measure and mark the length using a tape measure, then mark the cutting line with a pencil and a speed square.
Position the jigsaw in such a way that the blade sits on the waste side of the cutting line. Marking the waste side with an "X" will help and makes things a little easier too. Turn the tool on and wait for the jigsaw blade to pick up speed or rest it on the wood and then turn it on.
Some people like to start the blade while in contact with the surface and others like the blade running before starting into the wood.
The secret to doing straight cuts in 2x4 lumber is to guide the jigsaw steadily, in one go.
As long as the pace is slow and consistent, you will be fine by allowing the blade to do the work of cutting for you – keep the focus on following the cutting line as you control the speed and pace of the cut.
Make sure that the shoe is flat against the surface of the lumber, and that you are not tipping the jigsaw forward as you push it along (moving faster than the blade can cut).
TIP!
Do not hold the jigsaw too long in one spot. If you feel that the blade is meeting too much resistance, do not push the blade against the remainder of the material.
Stop the jigsaw and pull out of the cut entirely, and change the blade if you need to. Then start the cut again from the opening kerf of the cut.
Keep a consistent speed and pace and follow the cut through to the end. Make sure that you stay on the line, especially towards the end where the cut line becomes harder to see and the blade tends to veer right or left.
How to Make Bevel Cuts in 2x4 Lumber
When making bevel cuts in 2x4 lumber with a jigsaw, the way you control the power tool is even more important.
First, disconnect the jigsaw from the power source and unlock the shoe. Set it to the required angle, usually at 45 degrees. Lock the shoe in place, and check with a speed square or protractor to ensure that the blade is at the desired angle relative to the shoe.
Mark the cutting line on the wood. Clamp a straightedge at the right offset distance from the cutting line to guide the shoe of the jigsaw as you make the cut.
Carefully position your jigsaw so that the blade is aligned to the cutting line on the waste side of the cut. Turn on the tool and let the blade get up to the set speed.
With one hand on the tool and one thumb on the shoe giving it a bit of downward pressure, carefully guide the jigsaw along the clamped straightedge throughout the cut. Make sure to keep the jigsaw at a consistent angle, and focus on following the cutting line.
Throughout the length of the cut, let the blade do the work of cutting the wood, with minimal forward pressure from you. If the blade doesn’t make it through all the way, stop and check the blade.
Replace the blade as needed, and start again from the opening end of the cut. Finish the cut in one steady motion, with one hand guiding the jigsaw forward while the other maintains a downward force on the shoe.
Remember to follow through with your cut and try not to veer off course at the end, which is easy to do with the shoe at a 45 degree angle. It may be easier to use a square as a guide when you cut for these beveled cuts.
Tips on Using a Jigsaw on Thicker Wood Stock
Working with thick lumber using a jigsaw requires some technique and a good set of heavy duty blades. Avoid tilting the jigsaw forward or sideways during the cut, and focus on pushing it forward along the cutting line.
More importantly, give the jigsaw time to make the cut. All too often, users rush the cut and end up flexing their jigsaw blades and veering away from perpendicular.
Blades will wear out quicker when cutting thicker lumber so be mindful of this and keep an eye out for how the blade is cutting, especially when making several cuts.
