If you need to cut a lot of straight boards then you probably need a circular saw. These heavy-duty power tools are designed to cut straight lines in timber, man-made boards and stone with the right blades. They offer a major power advantage over jigsaws but are limited to straight lines - though most offer an adjustable base plate to make angled cuts. Saws come in various sizes with blade diameters between 150mm and 185mm. This also gives a maximum cutting depth, which will be anything up to around 65mm.
To provide a smooth cut, most circular saws offer a high power rating, starting at around 1000w and going up to 1500w. This helps maintain a high RPM for the cutting blade.
Adjustable base plate
A good circular saw will provide an adjustable base plate. This will enable it to be angled between 0 and 45 degrees and also enable you to adjust the cutting depth.
Most base plates will be marked with parallel lines but your circular saw should come with a rip guide that will help you cut a straight line.
Various replacement blades are available and tungsten carbide tipped versions will last longer and cut faster than plain steel ones. For masonry work cutting discs are required.