What is Circular Saw?
A circular saw is a power-saw using a toothed or abrasive disc or blade to cut different materials using a rotary motion spinning around an arbor. A hole saw and ring saw also use a rotary motion but are different from a circular saw.
A circular saw is one of the most common power tools in use today. A circular saw is a tool for cutting many materials such as wood, masonry, plastic, or metal and may be hand-held or mounted to a machine.
Circular saws make quick, straight cuts across a board (crosscuts) or along the board’s length (rip cuts). You can also set a circular saw to make bevel cuts. Standard components on a circular saw include:
A blade guard covers the blade when the saw isn’t in use and retracts to expose the blade during use. A footplate or shoe that steadies the saw against the workpiece. A depth adjustment to allow for workpieces of different thicknesses
A bevel adjustment that lets the footplate tilt in relation to the blade for making bevel cuts. Circular saw sizes are usually classified by the diameter of their blades. Sizes of 5-1/2 to 7-1/4 inches are the most common. There are also many options available on circular saws. Choose the best circular saw for your specific needs.
Parts Of Circular Saw
Knowing its parts makes using a circular saw easier.
- Handle and power trigger: While holding the handle to push the saw forward, squeeze the trigger to start the blade; release it to stop sawing.
- Trigger lock switch: This safety feature prevents the saw from being turned on if the trigger is accidentally squeezed. Deactivate it with your thumb and simultaneously pull the trigger to start the motor.
- Front grip: This secondary handle is for your other hand to help guide the saw along its cutting line.
- Blade guard: A retractable guard covers the circular saw blade when it isn’t operating. When the saw is lined up and ready to cut, the guard is lifted using a tab on its side.
- Shoe: Sometimes called the base of the saw, this is the metal rectangle that rests on top of the material being cut.
- Bevel adjustment knob: Loosen to adjust the angle between the shoe and the saw blade.
- Depth lock knob: Loosen this knob to adjust and set the blade depth.
- Power source: Depending on model, this could be a removable battery on cordless models or a power cord connected to an outlet.
- The blade’s sharp teeth are measured in TPI, or teeth per inch. A higher TPI gives a smoother cut that requires less sanding. Blades with a lower TPI produce faster cuts that are good for rough work. Multi-purpose circular saw blades are available but specially designed varieties should be used when cutting materials like metal, cement fiber board, ceramic tile or plastic.
The base of the circular saw, called the shoe, rests on top of the material being cut. For a regular straight cut, the shoe and the blade are at a 90-degree angle. The angle of the shoe can be adjusted so that body and blade of the saw are tilted to make a bevel cut-through material.
How to Use a Circular Saw?
Beginners can easily learn how to cut with a circular saw and safely control it to achieve successful results. Like any power tool, however, it can be dangerous if not used properly.
For a basic cut:
- Measure and mark the cut line.
- Clamp the material firmly to a workstation.
- Attach the appropriate blade to the saw.
- Set the blade depth 1/4-inch below the material you are cutting.
- Confirm the bevel angle.
- Plug the saw’s cord into a power source or attach its battery.
- Rest the saw shoe on the edge of the material and near the cutting line.
- Lift the blade guard.
- With the blade next to but not touching the workpiece, press the lock switch and pull the trigger to get the saw to full speed.
- Keep the shoe firmly on the surface and ease the saw forward to the cutting line while keeping the trigger engaged.
- Guide the saw along the scrap side of the cutting line, keeping the shoe flat
- Let the saw do its work. Pushing with too much force can strain the motor.
- Release the trigger to stop the blade when the cut is complete, then lift the saw and place it on the workbench.
How to Cut Straight with a Circular Saw?
There are two types of straight cuts a circular saw can make on a piece of lumber.
- A crosscut is a cut against the grain of the wood, such as when trimming a length of board to size.
- A rip cut goes with the grain of the wood and is usually a longer cut. The term “ripping” could also describe trimming a standard 4-feet x 8-feet piece of plywood to a size of 3-feet x 7-feet, for example.
Accuracy is important when cutting wood. To help prevent cuts from veering away from the cut line, watch the blade as it moves along the line and not only the guide markings that are on the saw’s shoe.
Using a saw guide will ensure the tool cuts in a straight path. Place a speed square across the board you’re cutting, with its lip hanging over the edge. Get your blade aligned with the cut line and slide the straight edge of the speed square against the saw shoe. Hold the square in position as you guide the saw through the board.
For longer rip cuts, such as for sheets of plywood, accessories like a saw guide can help you stay on track. You can create your own by clamping a 1-inch-thick board onto the piece you are cutting and using it as a guide for your saw.
Here are a few more tips to help you with crosscutting and rip cuts:
- Crosscutting with a Square: Special squares help guide the saw through a short cut. Put the raised edge against the stock and guide the saw along the other edge.
- Ripping with a Circular Saw: Cutting along the length of the board (ripping) is accomplished with the help of a rip attachment or by clamping a board in place as a guide. The rip attachment is fine for making narrow cuts. For cutting wider pieces, make a cutoff guide.
- Making a Ripping Cut-Off Jig: Make the jig from two strips of 3/4-inch plywood, each 8 feet long. One piece should be about 5 inches wide; the other should be as wide as the saw base plus 5 inches. Have the home center or lumberyard cut them so you’ll get straight cuts, then screw them together so that the edges align.
- Guide the saw along the fence piece, cutting the wider piece to width in the process.
- Place the cut edge of the jig along the line and clamp or screw it in place. Guide the saw along the narrower piece to cut along the line.
Types of Circular Saw
1. Worm Drive Circular Saws
Worm drive models are very common circular saws. The primary difference between these saws and the others is the mounting of the motor and the arrangement of the gears.
The saw is longer because the motor is at the back. The blade is also slimmer and longer than your average circular saw. The blade is usually on the left side of the motor. This arrangement puts the bulk of the weight on the right-hand side. If you’re a lefty, this could be problematic.
The big advantage is that the gear arrangement of worm drive circular saws produces a lot more torque. This extra kick comes at the cost of some speed, but it’s a reasonable trade-off when you need more power.
This design is ideal for plunge-cutting and for when you need to cut wider lumber. The placement of the motor also makes it easy to see where you’re cutting. On the upside, these models are among the most durable. On the downside, they’re clunky and can feel cumbersome in hand.
2. Sidewinder (In-Line) Circular Saws
Also known as in-line saws, sidewinders are more compact. The main reason is the parallel mounting of the motor. The motor is parallel to the side of the saw and blade, to the left of the blade.
As the motor effectively lines up with the blade, the saw is more compact. It’s far more user-friendly because it’s lighter. If you hate oiling up circular saws, look into getting a sidewinder. It doesn’t require oil at all because it has a closed-off motor.
With the motor on the left, the heaviest part of the saw balances on the workbench side of your project. This arrangement lends extra stability and makes it easier to make accurate cuts. The overhead cutting style does slightly obstruct the work surface, but you can adjust for this. These saws are very versatile and ideal for those situations when you need to cut fast.
They don’t quite have the brute force of a worm drive model, but they’re powerful enough for general projects. They’re suitable for work on the go and can handle projects of most sizes. If you’re cutting denser wood, choose a worm drive instead.
3. Hypoid Circular Saws
Don’t mistake these circular saws for worm drives. The position of the motor is pretty much the only similarity. What makes these models different is the gear alignment and transmission. These models don’t require oil because the motor is completely sealed.
This type of circular saw features Hypoid gears. These gears have a slightly offset spiral and meshing gear and are at a 90-degree angle to the axis. This combination improves the contact between the blade and your project.
Thanks to this improved alignment, the torque is better, and the cuts are more efficient. You can get away with a smaller motor as a result.
The motor is to the left of your blade, making it easier to see the cutting line. This model is more potent than a sidewinder and so better suited to projects that require more torque. If you’re cutting dense, wet, or thicker pieces of lumber, consider one of these.
4. Abrasive Circular Saws
The blades of abrasive circular saws are their main differentiating factor. Instead of teeth that chew through the material, the edge of the disc is smooth. These models work by using friction versus a toothed cutting edge.
The blades slice through hard-to-cut materials. The best options have a diamond or cubic boron nitride-edging. If you’ll be doing a fair amount of cutting, it’s worth investing in more expensive blades. This type of work is hard on blades, and cheap blades wear out very fast.
The design depends on what you’re using the saw for. Those used for cutting metal and tiles often use a table saw setup. On the other hand, those designed for cutting asphalt, concrete, and pipes look similar to sidewinders.
Whatever the setup, operating these models is different. Instead of moving the blade along your material, you pull it toward you. This change makes accurate cuts a lot easier.
5. Biscuit Joiners
Biscuit joiners, despite their quaint name, are quite useful. You’ll use them to join pieces of lumber without leaving visible marks. The saw, in this case, is usually smaller and lighter than other circular saws.
This is a specialized piece of equipment, so it’s not quite as versatile as the other types. That said, if you do a lot of cabinetmaking or joinery, you might find it a worthwhile investment.
It operates simply enough. Line up the pieces of wood you want to join. Lightly mark where you want them to join. Then move them apart again and line up your biscuit joiner with the first piece. Cut the first slot at the marked line. Then repeat with the second piece of wood.
You’ll end up with the two edges, each having a small slit in them. The actual joint is created by a small piece of wood known as a biscuit and strong glue. Apply the glue and insert the biscuit. From there, join it as you would a tongue and groove joint.
6. Carbide Circular Saws
The carbide in the title here refers to the blade itself and the material from which the blade is made. These blades are tough and can cut through metal easily. For regular lumber projects, this saw is overkill. If you’re cutting a lot of metal, or very dense wood and other materials, it might be worth it.
These saws come in one of three setups:
- Horizontal: To be used in a similar way to a billeting saw. The horizontal type is the type you’ll usually come across.
- Vertical: This setup makes it possible to stack your material so you can cut more than one piece at a time. This can be a useful time-saver.
- Pivot: You can use this model as either a layer saw, or a billet saw.
Whichever setup you choose, the primary advantage of these saws is that the design is heat efficient. Thanks to this, the cut edges stay relatively cool despite the friction. The cooling factor also allows for longer cutting times.
7. Concrete Circular Saws
You might also find these models labeled as slab saws. They can look like chop saws or come in a handheld setup. If you’re taking on heavy-duty projects, pairing a diamond-tipped blade with these models will allow you to cut through almost anything.
The saw itself is powerful. Changing out the blade type makes it more versatile. It’s not the best option for light-duty projects, because the powerful motor is tough on blades. The blades spin faster here, so you get more friction and heat, and so more wear and tear on the blades.
So, you’ll either have to work in short bursts, allowing the material to cool down periodically, or use water to cool the material. Water does reduce the dust kicked up, so that’s a plus.
8. Flip-over Circular Saws
These models are useful for general carpentry projects. They’re a hybrid between a table saw and a miter saw. The hybrid design makes these saws extremely useful. The blade is mounted, so all you have to do is put the saw into place and feed your material through.
The type of circular saw blade dictates what materials you can cut with this saw. If you do a lot of framing, you might find the miter saw function useful. This function allows you to create perfect mitered joints quickly.
These models rank among the most useful for the general carpenter and home DIYer. As they’re mounted, they don’t require a lot of strength to control. You can work for longer before fatigue sets in. The downside is that they do take up more space in the workshop than the typical handheld model.
9. Metal Cutting Circular Saws
As you might expect from the name, metal cutting saws cut through metal. These saws are usually smaller than your average worm drive saw. They’re also usually a lot more powerful. The design is more heat efficient. More importantly, perhaps, it also offers the user some protection against metals shards and sparks.
The downside is that the saw cuts at a reduced speed. A reduction in speed is a good thing when you’re cutting metal. Lower RPMs mean less friction and heat build-up. It might, however, feel somewhat excruciating when it takes longer to cut plywood.
The upside is that these saws are usually more compact. They use smaller blade housings, and this reduces the overall size.
Circular Saw Cutting Tips
Keep these tips in mind as you are learning how to use a circular saw.
- When appearance matters, make cuts with the good side facing down, as circular saws can splinter the wood on the top side.
- Making your cut line on masking tape can reduce splintering.
- Start over if you see that you’ve veered off from the cut line instead of trying to curve your way back on track.
- Don’t clamp both sides of a cut.
- For efficiency and safety, set the blade depth no more than 1/4-inch below the thickness of the board.
Circular Saw Safety
Safe operation is the most important part of learning how to use a circular saw. These power tools are easy to operate but care should be taken to prevent serious injury.
- Evaluate your tools and workspace for any hazards before you begin. This includes ensuring that your work area is tidy and your saw horse is level and damage free.
- Unplug the saw or remove its battery when changing blades and when not in use.
- Avoid dangerous kickback. Always use sharp blades that are intended for the material to be cut and follow the blade manufacturer’s guidelines.
- Do not attempt to turn on the tool when the blade is against material to be cut.
- Never force the saw while it is cutting. Allow it to cut at its own speed.
- Keep the circular saw shoe firmly placed flat on the cutting surface.
- Wait for the blade to completely stop before lifting the saw from a cut.
- Wear safety glasses to protect your eyes from dust or flying debris, use appropriate ear protection to dampen the loud noise and a dust mask to avoid inhalation of sawdust.
- Keep hands away from moving blades.
- Do not wear loose clothing or jewelry when operating the saw.
A circular saw can be a powerful tool to have in your arsenal. Learning to use one doesn’t have to be intimidating either, especially if you follow proper safety precautions from start to finish.
Circular Saw Blades
The right saw blade is a key part of a successful woodworking project. Learn how to find the best circular saw blade for your work.
Each type of circular saw blade is designed to cut different materials and work with specific power saws. Be certain the blade you choose is suitable for the material you need to cut and that it fits your saw. There are several specifications you need to consider.
Compare the blade diameter and blade type with the capability of your saw. Acceptable sizes vary by saw model but the following generally applies:
- Handheld circular saws accept smaller blades, those 4-1/2 inches to 7-1/4 inches in diameter. These are typically carbide-tipped.
- Tile saws use 7-inch or 10-inch diamond blades.
- Table saws and compound miter saws use blades 10 inches or 12 inches in diameter. Like those for handheld saws, the blades are usually carbide-tipped.
- Circular saw blades for metal, like metal-cutting chop saws (also called abrasive saws or cutoff saws), take 14-inch silicon carbide or aluminum oxide abrasive blades.
Check the size of the arbor hole (the hole in the center of the blade). It must fit the arbor or shaft on your saw. Many blades with a circular arbor hole include a piece you can knock out to allow them to fit saws with a diamond-shaped arbor.
Types Of Circular Saw Blades
1. Standard Circular Saw Blades
Standard circular saw blades are typically used to cut wood or wood composites. The number of teeth on the blade helps determine the speed, type, and finish of the cut. Blades with fewer teeth cut faster, but those with more teeth create a finer finish.
Gullets between the teeth remove chips from the workpieces. Expansion slots cut into the rim help prevent the blade from warping as it expands and contracts during use. They also reduce vibration, creating a straighter cut.
2. Continuous-Rim Blades
Continuous-rim blades are a type of diamond-edged blade (sometimes called diamond blades) designed for use on materials like tile and slate. Diamonds affixed to the edge of the blade cut through the material. These blades create a very clean finish. Some work in dry-cutting applications only, some are for wet-cutting applications and some can work in either application.
3. Turbo-Rim Blades
Turbo-rim blades are diamond blades similar to continuous-rim blades but have a serrated rim that cuts materials like brick and concrete. These blades cut more aggressively than continuous-rim blades but don’t leave as clean of a finish. Some work for dry-cutting only, while some are appropriate for both wet and dry applications.
4. Segmented Blades
Segmented blades are also cut with diamond edges but have a rim divided by gullets similar to those on a standard blade. The segments create the most aggressive cut of the diamond blades.
These blades cut more quickly than the other types and can handle tough materials, like brick and concrete, but leave a rougher finish. Like continuous- and turbo-rim blades, some work for dry-cutting, while others can handle wet or dry applications.
5. Abrasive Blades
Abrasive blades can cut materials like brick and concrete. Some abrasive blades are suitable as metal-cutting circular saw blades. Like the diamond blades, they don’t have teeth. They are cut with an abrasive material like aluminum oxide or silicon carbide.
6. Stacked Dado Blades
Stacked dado blade sets are wood-cutting accessories that include two circular saw blades as well as several chipper blades and shims. By stacking the blades or combining blades, chippers, and shims, you can cut grooves of different widths. These sets aren’t for use with handheld saws; they’re designed for table saws.