Selecting a Saw Blade for your Table Saw
When selecting the right saw blade, you need to take into account some variables: your materials and the direction of your cut.
Not all saw blades are treated the same, and you should know the difference between them before purchasing a blade.
The main features that vary on a saw blade are:
1) The number of teeth found around the circumference of the blade.
2) The depth of the gullets—the valleys found in between each tooth.
The purpose of a gullet is to allow room for the material to be removed from the work area. The number of teeth and the depth of the gullet will vary depending on the cut of the blade.
The three most popular saw blades on the market are the Crosscut, Ripping, and Combination blades. The Crosscut blade is used when cutting short grain, while the Ripping blade is for long grain. The Combination blade allows one to cut both crosscut and ripping using the same blade.
Depending on how the cut needs to be made, the proper blade should be used in order to give you an optimal cut and create a safe working environment.
Ripping Saw Blades
Ripping saw blades are designed for efficient and smooth ripping. The low tooth count from 24 to 40 and large gullets combine to make this blade fast and aggressive while making the cut absolutely flat and precise. When ripping wood one produces large chips because of the long wood fibers in the long grain. Therefore one would need large gullets to give room for large chips to be removed safely. Without the presence of these large gullets there is a danger that the blade could overheat and become dangerous.
Crosscut Saw Blades
Dedicated crosscut saw blades typically have 60 to 80 teeth. These teeth are evenly dispersed around the circumference of the blade and have an alternated tooth bevel, meaning that when you look at the edge of the blade you will see that the teeth lean in alternating directions. An alternative teeth bevel provides a cleaner cut. Additionally, the gullets on the crosscut blade tend to be somewhat shallow.
The reason for the large number of teeth and the narrow gullets is because of the structure of cross grain. As opposed to the rip cut, the cross grain creates small chips. With small chips, achieving cleaner cuts is done by increasing the tooth count. Because of the short grain, the wood being removed is mere dust and does not need large gullets to escape.
Combination Blade or General Purpose Saw Blades
The combination saw blade is designed to do both cross cutting and ripping. The design of this blade incorporates both the large gullets needed for a rip and the increased number of teeth needed for a crosscut.
There is one great advantage to using this as your dedicated blade: you don’t need to change the saw blade every time you need to rip or crosscut. Not only is changing the blade time consuming, but some of the larger powerful machines are bulky and awkward - making it difficult to change blades. The disadvantage of using this combination blade is that one cannot achieve the results of the Ripping/ Crosscut blades.
A dedicated Ripping blade and a dedicated Crosscut blade will enable one to achieve a much cleaner cut than a Combo. Let's be clear though, when using a high quality Combination blade, one can still achieve very clean cuts.