5 Tips on Using a Circular Saw

A Circular Saw is definitely a tool you should have in your starter DIY kit. They allow you to make larger, straight cuts on sheet wood, large bits of timber and can also be used as a plunge saw to cut large holes out of doors, wood, plasterboard etc! Before I do a full Tool 101, here's my top 5 tips on using a circular saw, for beginners.

Safety First

It may seem scary at first, but a circular saw really is such a great tool to help you with your projects, big and small. There's plenty of safety features built in, so don't worry. Keep your hands well away from the blade and make sure you're wearing safety goggles and a mask when using it.

Set the right depth

All saws have teeth. These are sharp and work by slicing through the wood at speed. One of the most important things you need to know when using a circular saw, is that the blade needs to be set at the correct depth to ensure a clean cut and smooth operation. Regardless of the material, the blade needs to be set one tooth deeper than the material, or 5-10mm deeper. This is not only for your safety, as it ensures as little blade is exposed as possible, but it's to prevent kickback, which is when the blade jams in the wood and essentially kicks back at you, either resulting in the saw coming away from the wood and potentially injuring someone, or the wood flying out from under you if not properly clamped. And believe me, you don't want either to happen!

To set the depth, first make sure you have unplugged or removed the battery from your saw. pull back the safety guard and hold it against your workpiece's edge. Loosen the depth adjustment and keep the base plate flush with the wood, lift the saw body up until the blade is at the correct depth, one tooth lower than the wood. Once at the correct level, tighten the adjustment knob and then plug her back in!

Support the material on both sides

When making any cut, the worst thing you can do is leave a side unsupported. This can cause the end of your cut to snap, it could fall on your foot (it's happened one too many times for me!), or if using a thin material like 3 or 6mm MDF, it could mean the blade gets jammed and kickback or your cut ends up wonky. Though your workpieces should be securely clamped down as good practice anyway, always support both sides of your cut adequately so that they do not move before or after cutting.

You can use a saw horse, a couple of clamps, or someone you know to hold it so it doesn't fall off. For sheet material, I tend to cut these on the floor and use 2x4s to raise it off the ground and support the sheet on both sides and at the ends. If you've got somewhere to store it, a large sheet of thick insulation foam board can be a great support for under your sheet wood. With this, you can just cut straight through the wood into the foam as it won't damage the blade, or mess up your cut.

Bevel cuts are possible up to 45 degrees

To get that waterfall edge on furniture or if you're cutting skirting boards, using the bevel cut function on circular saws can help you achieve this. There will be an adjustment knob on the front or back of your saw where you can tilt the base plate to your desired degree bevel. You may need to adjust your straight edge to account for the blade's new position.

Clamp a straight edge for a perfect cutting guide

Some circular saws will tell you what the measurement is from the blade to the edge of the base plate. If yours doesn't, grab a tape measure and take that measurement. Once you have it, transfer this onto the wood, measuring from the line you want to cut. You can then clamp a straight edge, such as a spirit level or piece of hardwood on this new mark and use it as a fence for the base plate to glide along to ensure you get that perfect cut.

Cut 'nice side' down

Blades on circular saws rotate clockwise, with the teeth facing the same direction. This means that it cuts the material from the bottom, up, making the bottom the clean cut side. If you want a particular side of the wood as your 'face' side, make sure you cut this nice side down to ensure there's no feathering or splintering when you cut.

The higher the 'T' number, the finer the cut

Saw blades come in a variety of types, some are for softwood, some are for hardwoods, metals, plastics, etc. The number of teeth a blade has is denoted by its T number. Most saws come with a 40T blade, meaning it has 40 teeth. The less teeth a blade has, the more rugged/rough the cut. Therefore the more teeth it has, eg. 100T (100 teeth), the finer and neater the cut. This also means smaller more delicate pieces of wood like moulding and trim, will need a blade with a high number to prevent it ripping and to prevent kickback from the wood getting stuck between the teeth.

Bonus tip: Use masking tape on your cut line to prevent tearout.