If you want to start a DIY project — or you’re already DIY-ing and looking to add a power tool — the circular saw is probably high on your radar.
This article walks through what makes a circular saw special and how to use one.
For total beginners, my recommendation on this site is to start with a jigsaw rather than a circular saw.
I have a separate article comparing the two — give that a look first if you’re undecided (Japanese version available; English forthcoming).
What Is a Circular Saw?
A picture is worth a thousand words — here’s a quick clip of a circular saw cutting through wood:
A high-speed circular blade slices through the lumber.
The circular saw is specialized for straight cuts.
It cuts fast and accurately.
The flip side: that high-speed blade is inherently dangerous (anyone with a vivid imagination can picture how things could go wrong…).
Heads up: a circular saw makes a lot of dust and chips. Working outdoors or hooking up a dust extractor is highly recommended.
What Makes a Circular Saw Stand Out
Now that you’ve seen one in action — let’s break down the key traits.
The basics
A circular saw cuts wood with speed and precision you can’t really match by hand.
The catch: it cuts only in straight lines — no curves.
・Straight cuts only
・Excellent precision and speed
・Some real safety risk
※ I’ll cover the most dangerous circular-saw failure mode — kickback — later in this article.
When the circular saw shines
So when is it worth pulling out a circular saw?
Here are the cases where I’ve personally felt it really earn its keep:
1. Wood deck builds (lots of cuts)
For projects like a backyard wood deck where you’re cutting tons of lumber, the circular saw’s speed really pays off.
You could substitute a jigsaw, but for raw efficiency, the circular saw wins.
2. Furniture / shelves (precision counts)
The circular saw’s accurate straight cuts are exactly what you want for furniture.
My personal arc with cutting tools went:
Hand saw (cutting was a chore) → jigsaw (was blown away by how easy a power tool felt) → circular saw (precision step-up).
You don’t have to use a circular saw — a jigsaw, or just having the home improvement store cut your wood, is fine for most projects.
I’d say upgrade to a circular saw once you’re seriously into DIY.
Buy a model with an aluminum baseplate
Precision is the circular saw’s main selling point.
So I’d skip the budget tier and go for at least a mid-grade model.
I started out with a cheap circular saw and ran into all the typical pain points: cuts that weren’t square, cuts that drifted off the line even when I was running it against a guide rail (turns out the cut position depends on how far the blade is extended), and so on.
Switching to a higher-end model was a revelation — much easier to use, and much more accurate.
● Specifically what should I look for?
→ A model with a precision-machined aluminum baseplate.
● Corded or cordless?
Cordless gives you the freedom to work anywhere.
That said, cordless models cost more than corded ones.
For corded, you can get into a top-tier model for under 30,000 yen (about $200) — so if your workspace has an outlet, I’d actually recommend going corded for the better price-to-performance ratio.
I have a separate Japanese article on the HiKOKI C6MEY (a corded high-end model) — what’s good about it and how I dialed in the calibration. (English version forthcoming.)
How to Use a Circular Saw
The basics:
Before cutting — set the blade depth
You can adjust how far the blade protrudes from the baseplate.
Hold the saw against the workpiece (with the saw off) and check.
You want the blade to extend a few millimeters past the bottom of the wood.
※ Always unplug the saw (or remove the battery) when adjusting.
Always cut against a straight guide
With a circular saw, always run the saw along some kind of straight-edge guide.
Two reasons: it gives you a clean, accurate cut, and any sideways force on the blade can pinch and trigger a “kickback” (more on that below).
Dedicated guide rails are sold at home improvement stores and online. Example:
If you enjoy DIY, building your own circular-saw sled / crosscut jig is also a great option.
I built one — the article (Japanese; English forthcoming) is worth a read if you’re interested.
Making the cut
As covered above: cut along a straight-edge guide.
① Spin the blade up first → ② then push forward into the wood
※ Important ※
Always start the blade before it touches the workpiece.
If you start the saw with the blade already touching the wood, you can trigger a “kickback” — the saw violently jumping back toward you.
And when the cut is done, wait for the blade to stop spinning before lifting the saw off the workpiece.
Pro tip: cut on top of foam insulation board
Setting your workpiece on top of a sheet of extruded polystyrene insulation (Styrofoam-like rigid foam, sold at home improvement stores) makes circular-saw cutting much more stable.
Especially helpful when ripping large panels.
Set the blade depth so it sticks just a few millimeters past the bottom of the workpiece (and into the foam):
Lay the workpiece on top of the foam and cut straight through. The foam gets cut along with the wood — that’s fine.
The workpiece stays fully supported during the cut, so it’s much more stable than balancing it across two sawhorses.
About Kickback
Kickback is when the blade catches in the workpiece and the saw violently jumps backward — toward the operator.
It’s the single most dangerous thing about a circular saw.
It can cause serious injuries.
The Japanese DIY YouTube channel “Kamiya-sensei’s DIY Channel” has a detailed video on kickback prevention. Linking it here:
The core defenses:
・Cut straight, with the workpiece fully supported (no flex / sag)
Foam insulation as a backer (covered above) and a proper guide rail both help a lot.
And to limit the damage if a kickback does happen:
・Don’t stand directly behind the saw
For hardwoods, the blade is more prone to binding. If that happens:
・Stop the blade and pull the saw straight back without spinning the blade
・If the blade is too stuck to remove, use a hand saw to relieve the cut.
(Useful to know.)
Wrap-up
That was the circular saw rundown.
It’s a major step-up tool for speed and precision — a real game-changer for DIY.
It does come with the kickback hazard, but if you understand how to avoid it, the saw is a powerful and dependable tool. Stay safe and enjoy the build!
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