When our contractor grandfather was building homes at the turn of the last century, 2 by 4s were a full two inches by four inches and the material was cut to size with a hand saw. Think what it would be like if a hand saw was the only means of cutting lumber when building a home today. It's hard to imagine a "construction world" without a portable electric circular saw.

Besides making the task of cutting wood easier, the circular saw has made housing more affordable. It allows a carpenter to perform his work in a fraction of the time that it would take using a hand saw. A home can be framed in less time, and time is money. A tool that costs just over $100 can save thousands on the price of a home.

Speed isn't the only advantage of a circular saw , there are several benefits, not the least of which is the vast array of material that it can cut. With the proper blade it can cut almost any material: wood, metals, plastics, fiberglass, cement block, slate and brick. On wood it can rip, crosscut, and make angle cuts. It's no wonder that a portable electric circular saw is probably the most commonly used saw.

A disadvantage of a circular saw is its need to be plugged into an electrical power source. For builders this had created the need for temporary power (or a portable generator) when building a house. For the do-it-yourselfer, it presents several challenges; finding an extension cord long enough to accommodate out-of-the-way projects and avoiding cutting the power cord.

However, thanks to recent developments in the power-tool industry, you can say goodbye to power cords and hello to the battery-operated cordless circular saw. Granted the cordless models don't have the infinite supply of power of their corded counterparts, but they are extremely convenient, powerful enough, and perfectly suited for the home handyman.

Regardless of the power source, a circular saw is ideal for cross cuts (cutting across the grain) on large or thick planks of wood, as well as for ripping (cutting along the grain). We typically make a pencil mark or snap a chalk line and make a fairly accurate cut using the saw freehand (without a guide) as the size of the blade keeps the tool roughly on the straight and narrow. Because of this, the circular saw is a favorite for quick cuts when accuracy is not an issue.

A circular saw also can be used for more accurate cuts by using a guide or fence to ensure that it stays on the correct path. Furthermore, when you need to cut a beveled edge (an angled edge) the circular saw often is your best bet.

To make the circular saw a truly versatile tool, buy the table saw attachment for your workbench. This allows you to fix the circular saw upside down so that it acts as a cheap table saw.

When looking to buy a circular saw, consider the following:

• Electric or cordless? Depends on how often you use it and the type of work you typically perform.
• How easy is it to replace the blade? Some saw manufacturers make this difficult.
• How large is the blade? The standard size is 7-and one-quarter inches: Anything less will limit the size of material that can be cut especially when it comes to a bevel cut.
• Will the circular saw cut bevels? The typical range should be 0 to 45 degrees.
• Can you adjust the saw table so that it will only cut to a certain depth? This is necessary for cutting small grooves, plywood and material of varied thickness.
• Can you use a dust bag or vacuum attachment with this saw? Circular saws can produce a considerable amount of dust.
• Can you attach a rip fence guide to the saw? This is useful for ripping down planks of wood or strips of plywood.
• When using the saw freehand, how easy is it to see where the blade is cutting? Many saws now have a "sight" at the front edge of the saw's base to make guiding the saw easier.

Just as important as the saw itself are the blades you use in it. Blades vary in number of teeth, style and hardness of teeth to fit a specific job.

When choosing a circular saw blade, consider:

• Crosscut blade: As the name implies, this blade is for cutting across the grain of material. It has a series of evenly spaced, medium-sized teeth that are set (bent) alternately to the left and right.
• Rip blade: This blade is designed to cut along the grain of the wood. The teeth on a rip blade also are set alternately to the left and right, but unlike crosscut teeth, they are sharpened on the top, not on the inside. Thus, they are like a series of chisels that scoop out wood as the saw moves with the grain.
• Combination blade: Incorporates features of both the rip and crosscut blades. It's the best choice for general shop and construction work.
• Plywood blade: Has many small teeth for a clean and even cut through plywood. Crosscut and combination blades can be used for plywood, but can cause splintering.
• Carbide-tipped blade: The best of construction blades. For general purposes (like the combination blade), but the cutting edges are made from extra-hard carbide steel. Especially good for cutting material of different hardnesses.
• Abrasive wheel: Like a thin grinding wheel, these blades are toothless. Great for cutting masonry, fiberglass and light metal.

Finally, a word of safety. NEVER pin back the blade guard on a circular saw. The guard is there to protect you from serious injury.