Guide written by:
John, DIYer & IT developer, Brighton
A circular saw will be your greatest ally when it comes to home renovation projects. But these tools aren't worth a thing unless you have high-quality blades. Looking for a good carbide-tipped blade for precise cuts? Follow our guide for everything you need to know about circular saw blades!
- Number of teeth
- Teeth type
Choosing the right circular saw blade for your job
When selecting a circular saw blade, it is important to consider the following:
- The materials you plan to cut (wood, composite materials, non-ferrous metals, plastic, etc.) will determine the notch or tip of the teeth;
- The tooth type (depending on the material to be cut and the type of cut desired) and the gullet (the larger the gullet, the faster the cut);
- the bore, measured in millimetres (mm), i.e. the diameter of the hole at the centre of the blade (can be reduced with reducing bushes);
- the blade thickness in mm;
- the depth of the cut which depends on the diameter of the blade (itself dependent on the type of circular saw);
- the material of the blade (the blade plate) and the tips of the teeth (according to the materials being cut);
- the number of teeth (the higher the number, the cleaner the cut), represented by the letter Z;
- the number of revolutions per minute (RPM), relating to blade diameter (to be checked against the capacity of the circular saw).
Note that expansion slots are incorporated into the saw blade so that the metal can expand when hot. Some logos and abbreviations may be specific to the brand or manufacturer.
Saw blade and teeth materials
Clean, precise cuts. Softwood and hardwood cuts, chipboard, non-ferrous metal profiles, plastic, plexiglass sheets. Intensive use.
C1, C2, C3, C4
Carbide 1, Carbide 2, Carbide 3,
Degree of hardness of carbide-tipped teeth; the higher the number, the greater the resistance of the carbide (remains sharp for longer but is more fragile).
TC or TCT
Tungsten carbide or tungsten carbide-tipped
Perfect for hardwood, softwood, chipboard and composite materials. Regular use.
For cutting double-sided melamine boards, MDF. Intensive use.
Carbide blade plate (uncoated teeth).
High carbon steel
High carbon steel; softer steel for cutting wood.
Bore and blade diameter
Blades are toothed metal discs featuring a hole in the centre called a bore. This hole is used to attach the blade to the saw. You can select a blade with a bore that has a larger diameter than the bore shaft of your saw provided that you use an reducer ring. The diameter of the bore must also be at least 5 mm smaller than that of the nut that attaches the blade to the bore shaft, for obvious safety reasons.
The diameter of the blade must not exceed the maximum diameter of the blade designed to be used with your circular saw. Buying a blade that is slightly smaller is not dangerous, but it will reduce the maximum cutting depth. If you're not sure, refer to the user guide of your saw or check the sizeof the blade currently on your saw.
The number of teeth on a circular saw blade
Saw blades are equipped with teeth; this is the part of the saw responsible for cutting. A blade with larger teeth spaced further apart is ideal for rip cuts. This is when you cut the wood with the grain. Large spaces between the teeth (called gullets) allow the sawdust to be expelled quickly.
Inversely, smaller teethallow fora better finish, particularly when making crosscuts. This will, of course, have a negative impact on the speed of the cut.
It is important to note that the gullet (the space between two teeth) is more important than the number of teeth. A 130 mm blade with 24 teeth will have the same gullets as a 260 mm blade with 48 teeth. In general, blades are marked to indicate whether they are designed for rip cutting, finishing work or if they are a combination blade.
Circular saw blades: tooth type and angle of attack
The number of teeth isn't everything as there are different shaped teeth for different purposes.
Alternate top bevel teeth (ATB)
Alternate top bevel teeth alternate between right-hand and left-hand bevels; these blades are common and multi-purpose. These teeth are used for cross cuts and finishing wood and veneered plywood.
Negative hook angle
These blades are designed for radial arm or mitre saws. Carbide tipsflank backwards to slow the feed rate. This also reduces the risk of kickback, improving safety.
Triple chip grind teeth
Flat top grind teeth alternate with teeth bevelled on both the right and left corners across the entire blade. The chamfered teeth make the rough cut and the flat teeth finish the cut.
Last but not least, a reduced attack angle cuts down on fibre tear-out. The combination of these features makes these blades ideal for finishing work. Flat trapezoidal teeth are sometimes abbreviated as FT.
Nail-resistant or trapezoidal teeth
Scrap lumber or demolition lumber may contain hard foreign bodies, such as nails or gravel, which can break a conventional saw blade. The teeth of these special blades are narrower and are made of a softer carbide that absorbs the shocks. These blades are perfect for disassembling wooden palettes!
A shoulder at the back of the tooth prevents the blade from getting carried away by limiting the amount of material cut by each tooth. Otherwise, there is a risk of kickback which could be dangerous. These types of teeth are found on blades with larger gullets.
HSS blades or carbide-tipped saw blades
HSS (high-speed steel) blades
These blades are inexpensive and can be sharpened easily – which is useful, as they tend to dull quickly. They are designed to be used with solid wood.
While increasingly rare for circular saws, you will often find 600 mm steel blades for log saws, which are used to cut up firewood.
Carbide-tipped saw blades
Blades with carbide tips can cut up to fifty times longer than all-steel blades. This type of blade is, therefore, a obvious choice when you are cutting hardwood , which can dull steel blades very quickly. This is particularly true for chipboard, MDF and plywood. Note that this type of blade is not as easy to sharpen.
Tungsten carbide is often abbreviated as TC or TCT (tungsten carbide tips); these blades are cheaper and less resistant (depending on thickness).
Saw blades for non-ferrous metals and plastic
Materials such as plastic or non-ferrous metals and light alloys cannot to be cut with just any blade.
Blades for this purpose are often made of tempered steel and have numeroustungsten carbide- or carbide-tipped teeth to ensure precise cutting.
These blades have a negative angle of attack to minimise the risk of kickback.
These blades are often referred to as multi-material blades.
5 points to keep in mind when choosing your circular saw blade
- Check the features of your saw. Once you know the diameter and bore size of your saw, you just have to select a blade to suit your needs.
- While log saws and mitre saws require special blades, the blade you choose for your portable circular saw will depend on what you will be using it for. Bear in mind that you will have to weigh up speed and quality of finish.
- The intended use of the blade is often indicated by the manufacturer, making it easier to narrow down your selection regarding the gullet size and tooth type.
- Universal, all-purpose blades offer a good compromise between speed and finishing quality if you do not use your circular saw on a regular basis.
- All the different logos and abbreviations can sometimes be confusing. In order to make the right choice, consider the manufacturer's recommendations, the material used for the tips of the teeth, and the type of teeth themselves.
Portable circular saw
Guide written by:
John, DIYer & IT developer, Brighton, 70 guides
Since I was a child, I was always interested in manual and technical works. Always fascinated by woodworking, I took advantage of my first flat as a playground. On the cards: electricity (of course, safety first!) and some partition walls; but also decorating with the help of the missus, made-to-measure furniture and little tricks to optimise the space, all the while remaining as original as possible. When the little one arrived, I started building bits and pieces for him! Lacking space, I have not got a permanent workshop and certain tools I dream about but are not part of my collection. Not to worry, I already know a lot about DIY and I have a high-tech profile that I hope will guide you in your decisions!