Circular Saw Buying Guide

What is a circular saw?

A circular saw, sometimes called a power saw, is a powered device that cuts with a rotating blade. Next to hammers and drills, circular saws are the most commonly used tools in home building and repair. Interchangeable blades on circular saws allow you to cut everything from lumber to concrete.

Circular saws have an electric or battery-operated motor that spins the blade. On some circular saws, this motor is mounted perpendicular to the saw blade. These circular saws offer a greater deal of control and reduce the chances of binding or a kickback, which can occur when the circular saw’s blade jams up in tough material. The price for the extra control is reduced cutting power.

For heavy-duty cutting, such as thick pine or hardwoods, a circular saw with a motor mounted parallel to the blade is ideal. These circular saws offer more torque directly to the blade and some models include geared speed settings.

The right tool for the job

Circular saws are measured by the size of their blades. The most common consumer choices range from 4-inch to 7 1/4-inch circular saws. Smaller 4-inch circular saws are lightweight and easy to maneuver, even if you’re working overhead or high on a wall. These circular saws work best with two-inch board stock, paneling, or plywood and flooring less than 1/2 inch thick.

Larger 6 ½ and 7 1/4-inch circular saws are the best choice for general use. The weight of these circular saws gives you more accurate control; they won’t bind on thicker stock or pressure-treated wood, and they’re far less susceptible to kickback. Unless you’re using only lighter building materials or doing a lot of overhead work, a 71/4-inch circular saw is the best choice.

You’ll need to consider horsepower and weight when choosing a circular saw. More horsepower is always better, as these larger circular saws generate more torque, which is needed for heavier cutting jobs. That extra horsepower will also prevent the circular saw from slowing down when it hits a knot or thicker material, which can cause the circular saw’s blade to burn wood or melt laminates. Look for a circular saw with 1.5 horsepower at a minimum for the greatest flexibility.

The weight of a circular saw is a matter of personal preference. Heavier circular saws will pull themselves through a cut, giving you more control than a lightweight circular saw that you need to push. Remember that you’ll need to lift and control the circular saw, so you want to choose a weight that won’t tire your arms after the first few cuts.

Circular saw guides and safety

Circular saws have bases with notches or blades that you use to sight the position of the circular saw relative to the line you’re cutting. Look for a short distance between the end of a circular saw’s blade and its guide—two inches or less is ideal. If you’re left-handed, look for a left-handed circular saw or one with a reversible base plate.

Several manufacturers have added laser guides to their circular saws. In theory, this makes it easier to know where the circular saw is going. In practice, a laser gives you no more control than a base notch, and the laser in a circular saw may get washed out in bright light. In addition, certain materials, such as fiberboards and laminates, generate clumping sawdust ahead of the circular saw’s blade that can interfere with the laser’s accuracy. Laser guides also add to the cost of the saw, but if you think you’d like to have the laser guides, choose a circular saw that also has guide notches for times when the laser guide isn’t enough.

Top blade guards and safety switches are essential safety features on any circular saw. The top blade guard should roll back easily during use, then snap immediately back into position when the circular saw is finished cutting. A safety switch is a button that must be depressed before the circular saw’s trigger can be pulled. The best-designed circular saws put this button above the trigger so that you can hold it in place with your thumb while you’re squeezing the trigger.

Adjustments and durability

The base plate of a circular saw supports its weight while you’re cutting. It also adjusts to control the depth and angle of the circular saw’s cut. You can tell a lot about the quality of a circular saw by the base plate adjustments. Look for an engraved bevel guide that won’t wear off as you use the circular saw. When you unpack it from the box, you’ll want the plate adjustments to move easily, even when they’re clogged with sawdust, and firmly hold any position you set.

A circular saw’s housing and base plate materials should be noncorrosive steel or heavy high-impact plastic. Circular saws with plastic housings are lighter than steel circular saws and very durable. Consider a plastic housing if you’ll be using the circular saw in the rain or around plumbing, as these circular saws are easier to grip when wet and less likely to conduct electricity to your hand.

Cordless circular saws

Battery-operated circular saws are the newest innovation available. These circular saws are rated in volts rather than horsepower, with higher-voltage circular saws delivering more cutting power and speed.

The light weight and freedom from cords makes these circular saws ideal for overhead work and rooftops, but they are a poor choice for general use. Most cordless circular saws can’t cut thick stock or pressure-treated woods, and extended cutting sessions will quickly drain the circular saw’s battery.

For lightweight materials up to 2x6s, including paneling, decorative pine trim, and shingles and siding, or in places where electrical access is inconvenient or impossible, a cordless circular saw is ideal. For general use, stick to a corded circular saw.

Need to know more?

• Using a Circular Saw
  http://www.popularmechanics.com/home_journal/tools/1303011.html
• Circular Saw Tool Profile
  http://homerepair.about.com/od/toolsmaterialsyouneed/p/prof_circ_saw.htm
• Selecting the Proper Saw Blade
  http://woodworking.about.com/od/toolsequipment/p/sawBlades.htm
• Hearing Protection
  http://www.askthebuilder.com/179_What_Did_You_Say_Hearing_Protection_.shtml