The circular saw is not just for professional carpenters. It is a versatile tool, suitable for many woodworking tasks. There are supposed to be more than 40 million portable circular saws in the US alone, so it is a popular tool. Here is a short introduction to circular saws for beginners.
Note that circular saws are not just for woodworking. With the right blades, circular saws can be used to cut many other materials, for example ceramic tiles and masonry. But in this article we will focus on cutting wood. The term circular saw includes a wide variety of circular saws but here we are focusing only on the portable electric circular saw.
Nowadays, you can choose between cordless or corded circular saw. The cordless circular saw has a number of advantages but it is not as powerful as the corded models. If you are going to cut harder material than wood, beware that the batteries will not last for long.
The worm drive circular saw was invented in 1923 by Edmond Michel. Later he and others created a company that later became Skilsaw Inc. They were successful in selling portable circular saws, even today you can hear the term Skil saw used for a portable circular saw.
Worm drive saws have the motor parallel with the blade. They have gears to increase the torque. In-line saws have the motor perpendicular to the blade.
By changing blades you can transform your circular saw to a new tool. Generally, you get a combination blade with the circular saw. Combination blades are good general-purpose blades for ripping and cross-cutting. But you also have a number of specialty blades. The most common are crosscut and rip blades. The crosscut blade is meant for smooth cuts across the grain. The rip blade is also known as framing blade, it is ideal for cuts along the grain. For smooth cuts in plywood and veneered stock, use a plywood blade.
Blades for wood cutting used to be made of HSS steel but carbide-tipped blades last longer and have become the most popular type of blades. Carbide-tipped blades hold their edge much longer than steel blades, they can also be sharpened several times.
Needless to say, safety is very important. A circular saw can quickly cause serious accidents. You need to pay attention to a lot of things. Always wear safety glasses, wood chips will be flying around. Make sure that the power cord is not in the cutting path. Never force the blade through a cut, allow the saw to cut at its own speed. Make sure that you are not cutting through nails, this can cause kickbacks. Make sure that the blade guard springs back over the blade before setting the saw down.