A good circular saw is critical to any serious woodworker and the go-to electric tool for most carpenters. The circular saw's versatility is partially due to the fact that it can be either table mounted or hand held. For straight cuts, it is recommended that a circular saw be clamped to the wood with a straightedge. This will give you a straight cut akin to a table or miter saw. A quality circular saw will also allow you to adjust the cut depth and angle of the cut.
When choosing a circular saw, there are three central questions you must ask:
Circular Sander
What kind of cutting power do you really need? There are two primary types of circular saws to choose from: worm-drive saws and sidewinder saws (also known as in-line saws). The big difference between the two is where the motor is situated and the torque that the motor placement provides.
On a worm-drive saw the motor is placed parallel to the blade which gives the saw considerable power. A worm-drive saw can cut through just about anything, even concrete, making it a popular choice for professional tradesmen. In fact, I would recommend that only professionals use worm-drive saws because of the inherent danger of wielding such a powerful tool.
If you are a more of a hobbyist, the sidewinder is a better alternative. Also known as an in-line saw, it also comes in two varieties, regular and small. A small sidewinder is a good pick for slighter body frames or people who prefer a lighter weight tool. While we are on the topic of safety, I cannot stress enough how important power tool safety is. Be sure to always wear protective gear! Also, I highly recommend a saw that features electric brakes. These "brakes" will reverse electricity flow when the trigger is released. This stops the blade in about two seconds flat and really improves the overall safety of the tool.
Is portability important? Electrical power tools can be cumbersome on the work site. If you want your circular saw to have maximum agility, I would recommend a cordless version. Cordless circular saws eliminate the inconveniences of lunging around extension cords and generators allowing you to easily navigate around a job and save time. With the cordless variety you will have to sacrifice some torque. Also, keep in mind that there is a time limit to any battery.
What kind of features matter to you? Think about the types of projects you plan on doing that will require a circular saw. How deep do your cuts need to be? The saw's blade capacity dictates the depth of the cut. Obviously, larger blades cut deeper, so make sure the blade is large enough to accommodate your project plans. Now consider how often you will need to change out the saw blade. Will you need to make different depth cuts and change blades frequently? If so, shaft locks make blade changes fast and easy and are worth looking for if you foresee having to make a lot of blade changes.