Circular saws are used for straight cuts in wood. They are extremely powerful and dangerous if used incorrectly. They are ideal for cutting manmade boards such as plywood and MDF and natural woods up to a size of approximately 60mm thickness. They are a necessary piece of equipment for heavy joinery work. They must be used safely as an accident with this type of equipment can be very serious.
- Robert Copcutt
- Mat Greenwood
- Hidde-Jan Lemstra
Health and Safety
- Power supply to be disconnected when changing blades.
- Be aware of were the blade is in relation to body parts.
- Wait for the blade to stop moving before putting the tool down.
- All cutting blades to be kept in their holders until they are required.
Slips, Trips and Falls
- Waste material/offcuts to be kept clear of work area.
- Equipment will be checked for defects before each use to minimise the risk of possible electrical faults or fire.
- Carbon Dioxide extinguisher to be available for any electrical fires
- The equipment will be checked before each use to ensure that there are no defects in the casing, battery or cutting head.
- Goggles, to be worn when using the equipment. Ear defenders and dust mask recommended.
- Fatigue contributes to most accidents so be sure to rest before it becomes a problem.
To get trained on the mitre saw and be added to the qualified user list, you will need to arrange for a training session with one of the circular saw owners.
Please watch this video before first using this saw. How to Use a Circular Saw (Video)
Please refer to the product manual for detailed instructions on how to use the circular saw. A printed copy is also kept with the saw. File:CircularSawManual.pdf
The base plate can be tilted to make angled cuts. Most saws adjust from 90 degrees to slightly less than 45 degrees, making it possible to cut bevelled ends on boards for corning attachments, hip-roof rafter cuts, and even miters. Most saws are equipped with a thumbscrew or lever to loosen the bolt which keeps the saw blade on the correct angle for the cut you are making, located on the front of the saw. Some are also equipped with a scale which indicates the blade angle, from '0' (90 degrees, or square to the board surface) to 45 degrees.
The blade can be set to the depth required for individual cuts, from less than 1/8 inch to the full depth the blade is capable of penetrating. The lever or thumbscrew which locks the base plate at the desired height is usually located at the rear of the motor on the left side.
Blade guard. This should be considered a essential safety feature, and has two parts, the fixed guard over the top of the blade, and the floating guard, which rolls out of the way as the saw is pushed into the work piece.
Support the material you are going to cut so that the blade will not react with anything underneath the cut as it is made. For example, do not lay a board on a floor or concrete slab for cutting. Sawhorses or a saw table are normally used for this purpose.
Mark the lumber you are going to cut to length, using a measuring tape, scaled rule, or stick rule, then use a square (either a steel square, tri-square, or angle square) to mark the path of the blade travel for the length of your cut.
Set the saw for the proper depth of cut. Don't have much more of the blade showing than you really need for the job you are doing. So to cut 40mm thick timber, set your blade to about 45mm or 50mm. This helps to minimize kickback.
Ensure the saw guard in smooth running condition. It should spring back in place as soon as you lift the saw off the work. It should slide up smoothly as you push onto the work. Make sure it's in the DOWN position before you put the saw down on the bench.
Look down the face of the right hand side of the blade and line it up to the pencil mark when beginning your cut.
Look at the front of the saw to the two guide notches. The right hand one is a guide for cutting with the blade set in the normal position, and the other one is for when the base angled at 45 deg. Line the notch up to the pencil line.
Start cutting, after a quick check to the front of the blade. Keep your eye on the guide all the time. This puts you in a natural position looking forward along the pencil line, and out of the way of any sawdust.
Keep an eye on the saw base as you are into the cut. Make sure that you are keeping the base of the circular saw flat on the timber being cut.
Push the saw into the material with enough force to keep the blade cutting, but avoid pushing so hard the motor speed seems to decrease, or binding occurs on the blade. A sharp blade should pass through any but the hardest materials with minimal effort.
Be sure the lower blade guard returns to its position when you exit the cut. Even a blade guard in good condition will occasionally bind if a piece of debris from the cut becomes lodged in its mechanism.
Tips & Tricks
- Be aware of the location of any power cords when operating a saw, keeping them behind the path of the cut at all times.
- Be aware of where cut off pieces of lumber will fall, to avoid injuries.
- Most the saws in this category are designed for right handed use. That is, when you are sawing in the normal position, the blade guard is between your face and the saw blade. If you are a left hander be aware that any chips of sawdust, etc. are flying out on your side. Don't forget your safety gear. They do make saws for lefties.
- When you place your wood before cutting, make sure the excess wood (the smaller piece) is free to fall once cut. If you cut between two points of pressure, the wood is likely to squeeze the blade once cut, and your more likely to get a kickback.
- A circular saw will almost always kick straight back. Watch your body position. Keep slightly to the side, and never keep a hand behind the blade.
Every month inspect for damage and general wear and tear and asses state of stock blades and replace as needed.
Every six months the carbon motor brushes should be inspected for wear, and replaced as necessary.