A circular saw is a handheld power tool with a high-speed steel blade for cutting wood and other materials. There are two main designs of circular saws, worm drive and side scroll drive. Worm drive saws have more motor torque, making it easier to cut thick, hard-to-cut materials, such as hardwood. A direct drive motor is attached to the blade, while a side scroll drive motor is attached to a gear that is attached to the blade. Side scroll drive or traditional circular saws generally have less torque, but the blade spins faster and costs less upfront.
Tip: If you plan to use your circular saw for heavy-duty cutting but don't want the added weight of a worm drive saw, choose a side scroll saw with a bevel gear that provides more torque.
Corded vs. Cordless Saws
The first thing to figure out is the difference between a corded saw and a cordless saw. Deciding which circular saw is best for your project depends on whether you want more convenience or more power.
Corded saws offer more current, or power, than cordless saws and weigh less. The steady motor power also means that corded saws can run longer without recharging.
With a cordless saw, you can work anywhere by plugging in a battery. Newer models work great with long-life lithium-ion batteries, but they generally have less torque or cutting force.
How to Choose a Circular Saw
Choosing the best circular saw for your project often means balancing cutting power or torque with the speed (or RPM) at which the saw blade rotates. Here are some additional features to help you choose the best circular saw for your project.
An easy-to-change blade system that changes blades in one step, with or without the tool. This is especially important to minimize downtime if you frequently change blades.
An electric brake quickly stops the blade when you release the trigger, enhancing safety and helping you get ready for the next cut faster.
A dust blower removes dust from the cut line for improved visibility. Additionally, a dust extraction port allows you to connect the saw to a shop vacuum or dust bag to collect sawdust as you cut.
A laser guide built into the saw projects a line on the work object to increase accuracy and efficiency for straight cuts.
A sawtooth guide increases accuracy and efficiency when cutting parallel to the edge of the workpiece. A longer guide bar or rail provides better control of the saw.
Quality Circular Saw Construction
There are a few things to consider when buying a circular saw.
Choose a heavy-duty saw base that can withstand a fall. Cast metal and ridged reinforced steel bases are more resistant to bending than flat aluminum or stamped steel bases.
Look for a magnesium alloy housing. It protects the motor and prolongs the life of the saw without adding too much weight.
A built-in work light improves visibility in low-light environments, eliminating the need for a separate lighting device.
Models with built-in rafter hooks provide quick, out-of-the-way storage between cuts and projects.
Top Circular Saws and Their Uses
Circular saws draw 8 to 15 amps (corded) and weigh only 4 to 7 pounds, making them ideal for light or heavy-duty home and professional use. Saw blades come in 5 to 10-inch diameters and can be mounted for right- or left-handed users. Here's a breakdown of circular saw types:
- Worm-drive circular saws weigh 13 to 15 pounds and are designed to handle demanding home or professional jobs, such as working with wet wood and tough materials like concrete.
- Worm-gear circular saws weigh 13 to 15 pounds and are suitable for demanding home or professional jobs, such as processing difficult materials such as wet wood and concrete.
- Their 12 to 15 amps (corded) provide more torque for smooth cutting of studs and plywood.
- Circular saws come with a rear-mounted handle for enhanced steering control, making them ideal for woodworkers.
- The motor of a circular saw is parallel to the blade. The blade diameter is 6 1/2 inches to 8 1/2 inches.
- Cordless circular saws weigh 7 to 10 pounds and come with a high-voltage (14.4 to 24V) battery for extended use.
- Cordless circular saws can be used almost anywhere, but they have less cutting power than corded saws.
- Smaller blade diameters of 5 inches to 7 1/4 inches are best for cutting thinner materials.
- Cordless saws are suitable for light to medium-duty home and professional use.
- Trimming circular saws are compact, draw 4 to 8 amps (corded), and weigh 4 to 7 pounds, making them easy to carry and operate.
- Trimming circular saws have very small blade diameters of 3 1/2 to 4 1/2 inches.
- They are best suited for jobs that require shallow cuts, such as finish carpentry work.
Choosing the Best Circular Saw Blade
Circular saw blades can be used for wood, laminate, aluminum, plywood, and other materials. Here are things to consider when choosing the best circular saw blade for your project.
The bevel feature of a saw blade allows you to tilt the saw bed to make bevel cuts. Look for tool-free adjustments and positive stops for increased efficiency and accuracy when adjusting for common angles.
The saw's depth of cut control is primarily determined by the blade diameter. Check the 90- and 45-degree depth of cut specifications to determine the blade diameter you need for the thickness of the material you're working with.
Tip: A crisp cut line is critical. If you are right-handed but prefer a saw with the blade on the right side of the motor, look for a groove on the upper blade guard for enhanced visibility.
Other Considerations
There are a few other things to consider when buying a circular saw:
- Number of Teeth:
- The number of teeth varies widely, from 14 to 120 teeth
- The more teeth, the cleaner and smoother the cut
- The larger the diameter of the blade, the more teeth you should have
Hook:
- The hook angle is the angle at which the teeth make contact with the material
- It is also known as the rake angle and determines the speed and smoothness of the cut
- It determines how quickly waste is removed
- A positive rake angle means the material is pulled in and is not recommended for harder materials like metal
- A negative rake angle is smoother and does not pull the material towards itself, making it safer but slower and removing less waste from the job site
Kerf:
Refers to the thickness of the teeth
It is also known as the cutting width
The thinner the kerf, the smoother and more delicate the cut
Thinner kerfs are prone to vibration and wiggle, so are not recommended for materials like hardwood
