Common Circular Saw Blades, how to choose the Best saw blade every time
I have been using my new circular saw which I recently bought to replace my old one because the motor burnt out after many years of loyal service.
It took me a little while to choose the right saw that would do all the jobs I would ask of it. I looked at loads of different types from all the top brands, and most of them are supplied with a basic circular saw blade fitted, and this got me wondering which type of circular saw blade is the most common? and what jobs can they do?
I followed my usual path and gathered all the information I found together to create a post to help you select the right blade every time, here are my tips on Standard circular saw blades:
The most common circular saw blades are 190mm (7 1/4″) and 165mm (6 1/2″) diameter, with 24 teeth (T) which are tungsten carbide tipped (TCT), have a bore diameter of 30mm (1 3/16″), supplied with bushes for smaller arbors. 24 T saw blades are used for RIP cuts, framing, and general cutting.
As I investigated I found that there is more to just blade size and the number of teeth when selecting a circular saw blade, things like Kerf width, tooth form, and materials all make a difference, and selecting the right combinations can mean the difference between a getting a clean, straight cut and a bad cut with tear out or even getting the dreaded kick-back, so read on for my guide to selecting a circular saw blade.
5 things to look at when buying a circular saw blade
Here’s my quick guide to buying a circular saw blade, you can use this for reference and read the in-depth deceptions for each one and find the find fact in the post below :
- Circular saw diameter – Make sure you fit the right size blade for your saw
- Number of teeth – Saw blades with a low number of teeth, 24T or less are for quick rough cuts, blades with a high number or teeth 40T or more are slower but cut much finer.
- Arbor size – Choose a blade with a bore diameter that fits your saw’s arbor most common is 16mm (5/8″)
- Kerf width – How thick the blades cuts through material
- Tooth shape and form – From ripping cuts to fine crosscuts tooth shape is important
What is the most common size of circular saw blade?
Circular saws blades are defined by several criteria, firstly by the blade diameter, as this dictates how deep a cut they can produce or what size lumber they can cut through.
The most common size of circular saw blades are 190mm (7 1/4″) diameter and 165mm (6 1/2″) diameter, which are offered by many big brands and manufacturers making them a great choice for DIY users and professionals alike.
Domestic use Circular saw blades range from 85mm (3 11/32″) diameter up to 355mm (14″) diameter.
Circular saws blades are available in many different types, for cutting different materials and making different cuts, and choosing the right type to fit your needs is very important.
So when making a choice you need to consider all the options otherwise you can end up with something that doesn’t work for you, and makes cutting difficult and even dangerous.
When selecting a blade for your saw don’t try to fit a blade with a diameter larger than specified by the manufacturer as this can be dangerous and the saw will not work.
The smaller 85mm (3 11/32″ ) circular blades are used with mini or micro saws for fine detailed cuts in thin sheet materials and are good for cutting through thin plywood, hardboard or aluminium,
Large 355mm (14″) diameter saws are often used by pros when constructing roofing or large timer frames.
The most common sized blades used in Mitre saws and table saws are 254mm (10″) or 305mm (12″) diameter. Mitre saws are used for crossing cutting long timbers and creating compound cuts. Table saws are used for cutting down sheet materials and fine, accurate wood working cuts.
The most common size for Chop saws is 355mm (14″) diameter, Chops saws are used for cutting ferrous and non-ferrous metal bar or box sections.
You can find our more about circular saws in our previous post, which will give you tips on buying the right saw for your needs, use the link Circular Saws
How many teeth do circular saw blades have and which is best?
I found that the second most important criteria when selecting a circular saw blade is the number of teeth.
The most common number of teeth on a circular saw blade is 24T. Blades with 24T are multipurpose and are good for general use. Blades with a high number of teeth, 80T and over, are used for very fine work and make clean, straight cuts. Blades with a low number of teeth, less than 20T, are for quick ‘Rip’ cuts for rough, fast cuts.
The general rule of thumb I use when buying circular saw blades is that the higher the number of teeth the finer and slower the cut will be, a low number of teeth will give a course and fast cut.
Choosing the right number of teeth on your circular saw blades when cutting wood, can make the difference between a great job and just making scrap.
I find that a fine blade with more than 40 teeth will cut well through plywood and veneers with very little tear-out and leave a good, clean, cut edge to the material, these blades are designed to remove a little bit of material each time the tooth cuts through and means that cuts take longer but are finer
To make quick ‘Rip’ cutting along the grain a good quality 24 toothed TCT blade will make quick work and leave a reasonable edge to work with.
Check out the handy table below for referencing what type of blades work best with different materials and types of cut.
| Material | Type of cut | Number of teeth | Hook Angle (deg) | |
|---|---|---|---|---|
| Solid Wood | Multipurpose Cuts | 24T | 15 - 25 | |
| Solid Wood | Ripping Cut | 24T | 15 - 25 | |
| Solid Wood | Cross Cut | 36T-40T | 15 - 25 | |
| Solid Wood | Ripping and Cross cut | 36T - 40T | 15 - 25 | |
| Laminated Board | Multipurpose Cuts | 40T - 60T | 5 - 15 | |
| Composite wood | Multipurpose Cuts | 40T - 60T | 5 - 15 | |
| Veneered Wood | Multipurpose Cuts | 40T -100T | 15 -25 | |
| Picture Frames | Multipurpose Cuts | 60T - 100T | 15 -25 | |
| Non-Ferrous metal | Multipurpose Cuts | 60T | 0 - 10 | |
| Ferrous Metal | Multipurpose Cuts | 36T - 90T | 0 - 5 | |
| Plexi-Glass | Multipurpose Cuts | 0 - 10 | ||
| Plastics | Multipurpose Cuts | 0 - 10 | ||
| PVC | Multipurpose Cuts | 5 - 15 | ||
| Solid materials | Multipurpose Cuts | 15 - 25 |
What’s the most common arbor size for a circular saw?
The next detail I look for when selecting blades for circular saws is the arbor size. The arbor is the metal shaft fitted to the saw which the blade mounts on to and is driven by the saw motor.
The most common arbor size for a domestic circular saw is 16mm (5/8″) diameter. Standard circular saw blades have a 30mm (1 3/16″) diameter bore, with metal, reducing spacers supplied to allow the blade to fit a wide range of saws. Large diameter saws are fitted with a diamond-shaped arbor to transfer the power.
Most aftermarket circular saw blades are made with a 30mm (1 3/16″) diameter bore through the center, they are normally supplied with a set of metal, reducing spacers that have a 30mm outer diameter to fit the blade, and then each spacer has a smaller bore which will fit over the arbor of the saw, this holds the blade on the centerline.
Some large diameter circular saws use a diamond-shaped arbor, this helps to transfer the saw’s power and torque and drive the blade through tough heavy-duty cuts.
Standard circular saw blades are locked onto the arbor with a metal washer and drive nut. the blade is clamped by the nut and washer to a shoulder on the arbor. Tightening this nut is important to stop the blade from slipping when cutting hard or thick material.
What is the most common Kerf width for a circular saw?
The fourth detail I found to be important when buying circular saw blades is the cutting width also known as the ‘Kerf’, this tells you how thick a cut the blade will make through your material.
The most common size for circular saw blade kerf or cutting width is 2.6mm ((7/64″). The Kerf is the width of cut the saw blade will make through the material. Kerf widths vary from 1.5mm up to 3.5mm for circular saws.
Circular saw blades with thinner kerf widths remove less material when cutting, and this makes them quicker, and they require less power to drive through the material. However, being thinner means they are not as stiff as thicker blades and this can be an issue when making heavy-duty cuts through thick or dense materials.
Fun Fact!: The word ‘Kerf’ orignates from the old English word ‘Cyrf’ which is ‘the act of cutting’
Blade manufacturers like Freud, Trend, and Irwin often produce the same blade sizes with different kerf widths, Full Kerf, and thin Kerf giving you the option that will fit our needs and your saw.
What is the best material for a circular saw blade?
As with most things you get what you pay for and circular saw blade quality is no exception, but you don’t need to spend lots of money on high-end blades all the time,
There are a couple of things I found as I was looking at options for saw blades, firstly the different grades of blades.
The best quality circular saw blades are made from high-grade carbide steel and are fitted with large high-grade tungsten carbide tips (TCT), which can be sharpened multiple times. The Blades are precision laser cut and perfectly balanced to remove vibration and Teflon coated to reduce friction and provide corrosion resistance.
Premium grade saw blades made by companies like Freud, which are made from really good quality carbide steel blades, with high-grade Tungsten carbide tips, these blades can be reground or sharpened many times and have a performance coating like Teflon to improve cutting and provide corrosion resistance to improve blade life.
A good quality blade is often produced with relief slots, which help to reduce heat and expansion during cutting, and will have all the blade’s details marked clearly on the side.
Lower-grade, cheap saw blades are usually made from stainless steel or High-speed steel and have smaller or no blade tips which can only be sharpened a few times before the hardened tip is gone.
I found that most good quality circular saws like these from Hikoki or Dewalt are supplied with a medium quality, general-purpose Tungsten Carbide tipped (TCT) blade which means you can start using them straight away, but it is always a good idea to invest in some aftermarket blades which allow your saw to be even more versatile.
What is the circular saw tooth form and shape?
Circular saw blades have lots of teeth and the shape of the teeth is as important as the number on the blade. There are several types of shapes, each with its own benefits. Manufacturers like Freud Offer Circular saw Blades with various types of saw tooth shapes.
See the table below which shows the options Freud produce or follow the link to find out more from Freud tools
| Tooth Shape | Suitable for | Image |
|---|---|---|
| Flat Tooth | Ripping Soft and Hard-wood |  |
| Double Triple Chip Tooth | Ferrous Metal and solid materials |  |
| Conical Tooth | Scoring Laminates |  |
| Bevelled Tooth | Ripping and cross cuts in soft and hard-wood, Chipboard, solid wood with nails |  |
| Flat-Triple Chip Tooth | Laminates, Chipboard, MDF, Plywood, Plexiglass, Plastics, Non-Ferrous Metals |  |
| Inclined tooth | Cross cutting soft and hard-wood, Laminates, and Plywood |  |
| Pyramid tooth | PVC, and Non-Ferrous metals |  |
| Axial Tooth | Cross cutting soft and Hard-wood, Picture frames, Plexiglass, Plastics |  |
| Rounded tooth | Ripping soft-wood |  |
| Alternative Top Bevelled Tooth (ATB) | Ripping and cross cutting soft and Hard-wood, Chipboard, MDF, Plywood, Picture frames |  |
Besides the profile of the tooth circular saws blades have two other important factors which can affect the way they cut through material, these are:
- Gullet
- Throat
The gullet is the distance from the tip of the blade to the bottom of the tooth relief, a deep gullet will help clear away material quickly and the shape can help prevent kick-back
The throat is the with of the gullet area, a wide throat will also help to clear material away from the blade during cutting.
Circular saw blades with a low number of Teeth tend to have large gullet areas, this is one reason they are good for fast rip cuts. whereas blades with a high number of teeth will have a smaller gullet area and throat to allow more teeth to fit.
The shape of the tooth has lots of details like rake angle, hook angle, clearance angles and lots of manufacturers have their own figures and designs which claim to be better than the competition.
Generally, these details are not critical to remember for most DIY circular saw users, as the description for the type of cut will give you all the information you need when choosing a blade.
It’s really only when you are looking at fine, precision work or are a professional that these details will be more important and useful to know.
What do Circular saw blade markings mean?
Throughout my researching Circular saw blades, I found that good quality blades were always marked with the blades critical information, such as diameter, number of teeth, and direction of rotation etc.
Circular saw blades should have good, clear markings, identifying the blades critical information, this is important so that you can check you have fitted the right type of blade to your circular saw, even if you have lost or discarded the packaging.
I often find that after a while these markings can wear off or become covered by swarf, and it is a good idea to regularly clean your saw blades to keep them in the best condition and that you can see the markings clearly.
To help make this easier I always clean my saw and the blade before I put my tools away after I have finished a project, whilst I am cleaning I can check the saw blade and saw to ensure they are both in good condition with no damage that might cause problems like poor cutting performance or tear out, keep the blade in good working order will also help avoid kick back.
For more information on Circular saws and the most common sizes, check out our previous post which compares the leading brands and has lots more details about how to choose a new circular saw, use the link to our Circular Saws Post
This article was written by: Richard Quinton – The DIY Help Desk Owner, Engineer & technical specialist.
Richard is one of the key partners in The DIY Help Desk team. He is a qualified Engineer, writer, and publisher, educated to Master’s level. He is a keen advocate of DIY and home improvements.
Richard enjoys helping others to learn new skills and reach their goals and believes that passing his knowledge and experience on through his writing is an effective way to positively impact the lifestyles and well-being of others on a larger scale.
