Last Updated on August 31, 2022 by Barry Gray
Circular saws are versatile, powerful tools that every woodworker can benefit from. But they can be hard to control, so getting a straight cut with one can be a challenge for some people.
Fortunately, there are quite a few well-developed methods for making straight, clean cuts with circular saws.
Whether it’s with a speed square, cutting guide, saw track, board clamps, or a universal rip cut sled, there’s a wide variety of ways to make sure your circular saws cut straight every time.
Using a Speed Square
A speed square (or rafter square) is a somewhat ironically-named metal triangle used to help make straight cuts with all kinds of tools. It’s an inexpensive, versatile tool that you can easily take with you wherever you need it.
The speed square is especially useful if you plan on making a cut at a 45° angle. That’s because the triangle’s longest line is at a 45° angle, so it’s simple to draw a perfectly straight line at that angle and mark your cut ahead of time. That way, a speed square can help you quickly make guidelines for when you make the actual cut, making it much easier to make a straight cut.
You can also use the speed square as a physical guide. You just guide your circular saw’s shoe along the side of the speed square to cut along its exact 45° angle. Of course, you’ll have to adjust where you place the speed square to adjust for the width of the saw’s shoe, but that’s a simple and minor change.
The speed square also has a 90° angle, so if you want to make a perfectly perpendicular cut that’s just as easy as the 45° cut. All you’ll need to do is mark the line you want to cut along, and make the cut with your circular saw. By marking the cut ahead of time, you make it easier to have an exact measure at just the right angle.
Just like with the 45° angle, you can also use the speed square’s 90° angle as a physical guide. If you place the saw’s shoe next to the speed square, you can make a perfectly straight cut by following the metal square’s right angle.
How to Use a Cutting Guide
A cutting guide can give you similar benefits to a speed square, but it can be even more versatile. However, you might have some issues with using your cutting guide at odd angles, and it can be a little more difficult to move around from place to place.
A cutting guide is a straight piece of metal or wood that you use to guide your circular saw. You can either make it yourself or buy one for less than $100. They’re great tools for making straight cuts, although they have certain benefits and drawbacks.
There are two kinds of cutting guides, the straightedge guide and the square-edge guide. A straightedge guide is just what it sounds like: it’s a straight edge that your saw’s shoe can press against as you make your cut, letting you make straighter cuts. If you use a speed square as a cutting guide, it’s a straightedge guide.
On the other hand, a square-angle guide lets you rest your saw’s body on top of it, with the sawblade at the guide’s edge instead of the saw’s shoe. It’s a great type of guide for making precise cuts, since it lets you see exactly where your blade is cutting. However, this guide can be tricker to make, and it can also create issues if your sawblade runs into the guide itself.
To use a straightedge guide, run the saw’s shoe alongside the edge of the guide as you make your cut. If you want to make a cut at an odd angle, you’ll want to mark the angle ahead of time and make sure that the guide is steadied before you make the cut.
A straightedge guide can also be imprecise, since you’ll need to precisely measure the distance between the saw’s blade and shoe in order to place the guide accurately.
To use a square-angle guide, you’ll want to place your saw’s show on top of the lower part of the guide. The guide should have a higher straightedge that you can run your saw’s show alongside as your blade falls on the other side of the guide, cutting directly into the material below.
Although a square-angle guide is a little more complicated, it makes it much easier to see where exactly you’re cutting.
Straight Cuts with Saw Tracks
A saw track can also help you make straighter cuts. Although it can be a more significant investment than a cutting guide or a speed square, it makes up for it with the benefits of precise cutting.
Unlike a cutting guide, a saw track attaches to the bottom of your circular saw and holds your workpiece in place while you make your cut. You can get pre-made tracks specifically designed for various brands of circular saws either online or at your local hardware store.
Like a straightedge guide, you can use a saw track to make odd-angled cuts. If you want to do that, you should attach a piece of lumber to the track and use it a s a guide when you make the cut. That’s because the track is designed to be used only at right angles where it can properly clamp on to the cutting material.
While you may be tempted to just use the track itself as your guide, that isn’t the best idea. That’s because a track that’s mounted too low will cause your sawblack to kick up the material as it cuts, which can cause kickback accidents.
But unlike straightedge guides, there’s no need to worry about measuring the distance between your saw blade and the shoe when you’re using a saw track. Instead, you can position the track on your workbench so that the bottom of your track and the material you’re working on are at the same height. That lets you cut directly into the material, and the track gives you great visibility into where exactly you will cut.
To use a saw track, just place your circular saw along the track, making sure that it’s well-attached. Attach either end of the track to the material you’re cutting, to make sure that it stays still and you get the straightest cut possible. Then, you can go ahead and cut exactly along the track, without having to worry about the kinds of problems that other methods can often face.
Use Board Clamps for Straight Cuts
The simplest way to get straighter cuts with your circular saw is by using board clamps. Board clamps are just what they sound like: simple clamps that attach a board to something else. They’re common tools that every woodworker should have, but you might be surprised by just how much they come in handy.
The best way to use board clamps to get straighter cuts is by using them to attach the material you’re cutting to a larger, more steady object. For example, you could attach the two-by-four you plan on cutting to a larger table. You can also use scrap wood as a stabilizing base, although you’ll want to make sure it’s very steady.
Once you’ve attached the material you’re cutting to a more stable object, the rest is simple. You just make the cuts you need to while avoiding cutting the board clamps. You should also consider whether you’ll want to reuse the stabilizing material. If you don’t, you can cut through that base. Otherwise, you should be sure to avoid cutting it.