Unless you are an advanced saw user, you most likely do not have any idea which blades are the right ones for your job and saw. Especially with carbide circular saw blades, there are so many designs, choices, and configurations, it can be incredibly overwhelming to first-time and even regular saw users. Below are some basic guidelines so you can make an informed decision in regards to the correct saw blade for your job.
Size and Diameter
While this factor may seem somewhat obvious, it is not uncommon to encounter saw users who want to use a different size blade than their saw to save money. You should never do this, because you will not get any clearance with your cut. In other words, a larger blade will not be able to clear the blade guard on a miter, the throat plate on the table saw, or the radial arm.
With a smaller blade in a larger saw, you will not be able to get a deep cut. Not only that, you will be messing with the correct geometry and design of the blade. Smaller saws run at a higher RPM, so the larger the saw, the lower the RPM. Blades are intended to work in concert with the saw, so you achieve optimal performance. If you mix and match blades, you are not going to have the most efficient cut.
Purpose or Material
You may encounter some problems if you are trying to buy a blade at a hardware store, because usually they only sell blades that are meant for cutting word with hand-held saws. However, if you are shopping online from a reputable dealer, you will have the option to purchase specialty blades that are listed by material and purpose. It is crucial to buy a blade that is designed for the material you want to cut.
While the price of a twenty-four-rip blade may make it an attractive option, you will be extremely frustrated when you try to crosscut with it. Similarly, if you attempt to rip solid wood using a trim blade, you will end up burning more wood than you cut. Use either blade to cut through laminate flooring, and you will really regret it when the top layer chips and the blade becomes dull after a few cuts.
Laminate flooring is extremely durable because it has aluminum oxide in it, so it makes sense to use an aluminum cutting blade. Saw blade manufacturers create blades for the professional, make a number of different blades with different configurations and with different uses, and identify them accordingly. Always follow their recommendations.
Type of Saw
Different types of power saws work most effectively when using the blades that are made for them. For example, if you use a rip blade on a radial arm saw, it is going to want to lift the wood right off of the table. If you attempt to crosscut with anything that remotely resembles a rip blade on the same saw, the whole carriage will try to run straight out toward you. Not only that, the teeth will dig in and jam up your saw, tripping up a breaker.
There are some kinds of blades, such as metal cutting blades, that are recommended for all kinds of saws: miter saws, table saws, and radial arm saws. However, it is recommended that you just stick with whatever the manufacturer recommends. Buy a miter blade for a miter saw; a table saw blade for a table saw, and a radial arm blade for a radial arm.
Generally, this is the easiest of all the precautions to remember. For more finished and cleaner cuts, you will want a higher tooth count, regardless of the material. When you are cutting through a thicker material, you will want fewer teeth. However, if you plan on using your saw as a multipurpose cutting tool, you will want to find one with a reasonable blade number. With a radial arm or a miter saw, sixty is an ideal number, as forty will rip out trim work, and with eighty it will be a battle to cut through a basic two by four.
Table saws generally fall between forty and fifty, and a vast majority of manufacturers make combination table saw blades with tooth counts in this range, so that they will work. The biggest exception to this rule is when you are cutting through plastics. It very much depends on the kind of plastic, whether it is brittle and hard, or soft with a lower melting point. Too many teeth will create melting, which will gum up the teeth and create a poor quality cut. Not having enough teeth, especially with a hard plastic, will cause excessive chips.
Rake or Hook Angles
When you are thinking about a blade for your particular type of saw, this is one of the more important considerations you can make. When you combine this factor with configurations and tooth shapes, the factor of rake angle will alter the blade’s entire purpose.
As far as your saw is concerned, you do not want to use a positive hook with a radial arm. Depending on what you are cutting through, a miter saw works the best with neutral, negative, or slightly positive hooks.
Typically, harder materials necessitate using a negative hook or a neutral hook angle. Especially if your wood is prone to tearing out when you are crosscutting, such as a softer conifer wood, a negative hook is more ideal.
Tooth Design and Configuration
This can be one of the more confusing concepts to grasp because of all of the conflicting claims and theories from manufacturers. Here are a couple of the most common types of teeth designs:
ATB w/Raker – Commonly referred to as a “planer” blade, this typically combines four ATB teeth with one flat top raker tooth for clearing out the cut. It makes for a true multi-purpose blade for your table saw, whether you are cutting through plywood, crosscutting, or ripping.
High or Steep Alternating Top Bevel – This tooth design, mixed with a neutral or negative hook or rake angle, is utilized when you are cutting through fine veneers. The biggest disadvantage to this design is that the drawback of this kind of tooth depends on the very pointed teeth, and the more pointed they are, the quicker they become dull.