Circular saw blades are the most frequently used cutting tools in most woodworking operations. These tools include the table saw, radial-arm saw, power mitre saw, and handheld circular saw, and blades made for each of these machines have many similarities-often, a single blade can be used on multiple tools. As your woodworking talents and expertise grow, you'll probably find it handy to have three to five different blades, each one dedicated to a specific style of cutting. Choosing blades for any of these tools necessitates weighing various choices.
1. Blade Size
The first option is to change the size of the blade. The diameter of circular blades is used to identify them, and each saw specifies the largest blade that would fit the instrument. Handheld circular saws normally employ 7 1/4-inch or 8 1/4-inch blades, while speciality panel saws accept blades as small as 4 1/2 inches and contractor-grade worm-drive circular saws accept blades as large as 9 inches.
The most common blade size for stationary saws (table saws, radial-arm saws, mitre saws) is 10 inches, while 12-inch saws are also available. There are also 8-models, but these are usually very lightweight saws that aren't ideal for major woodworking jobs, while they can be adequate for amateurs who just work on little craft items.
While it is not normally suggested, a smaller blade can be mounted in a saw designed for a larger blade size. However, you should never mount a blade that is larger than the maximum size stipulated by the saw.
2. Material to Be Cut
Many blades are touted as being suited for cutting a wide range of materials, but manufacturers also sell blades built specifically for certain types of building materials. Blades, for example, can be selected for plywood, melamine, or laminate. This marking primarily ensures that the tooth count and size are acceptable for the material. This is not to imply that a good-quality combination or general-purpose blade cannot be used to cut certain materials; nevertheless, if you cut them frequently, you may wish to invest in blades designed specifically for them.
3. Basic Blade Types
The fundamental kind is the next-and possibly the most significant distinction to make when selecting a circular-action saw blade. Circular-action saw blades fall into four broad categories:
Crosscut blades have teeth with sharp chisels welded to the tips, which are commonly constructed of carbide steel (these blades are often marketed with the phrase "carbide-tipped). The teeth and cutting chisels of these blades are slightly inclined ("set") such that the alternating teeth point in opposing directions. This results in a slightly wider cutting slot (kerf), which improves the efficiency and cleanliness of the cutting process. On most materials, this can result in a very fine finish. Because cutting over wood fibres is more difficult, these blades tend to have smaller, more numerous teeth. Crosscut blades are the only type used on mitre saws and are used on table saws and radial arm saws.
Rip-cut blades are designed to cut wood parallel to the grain. The teeth of a rip-cut blade are fewer than those on a cross-cut blade, but they are longer and have deeper gullets between them. This aids in the removal of material when it is sliced. Rip-cut blades are capable of cutting swiftly. They are frequently used for ripping on table saws and radial arm saws, but never on mitre saws, which exclusively conduct cross-cutting.
Combination blades are designed with a form that combines the advantages of rip-cut and cross-cut blades. They are constructed in such a way that a rip tooth alternates with every few crosscut teeth. These blades are a fantastic choice for inexperienced woodworkers who don't want to switch between cross-cutting and rip-cutting activities frequently. They are commonly found on table saws and radial arm saws.
General-purpose blades are commonly confused with combination blades since they serve the similar purpose of crosscutting and ripping cutting with equal efficacy, but the design is distinct. The teeth on a combination blade are all the same size and shape, but slightly bigger, with a more pronounced bevel on the cutting edges. For many woodworkers, these blades have begun to replace classic combination blades.
4. Speciality Blades
While basic crosscut, rip-cut, combination, or general-purpose blades will handle the majority of cutting tasks in a woodworking shop, there are additional specialist blades that many experienced woodworkers find useful:
Panel blades contain a high number of tiny teeth and a less severe hook angle. They're made to make clean cuts in panel sheet goods including laminates, plywood, and solid-surface material. These are typically used on materials that will chip or break if cut with standard circular blades. These blades are sometimes specified for a certain material and can be labelled in a variety of ways, including "laminate and plywood," "industrial glue" (made to cut through the glues used in plywood), and "solid-surface" (for cutting materials such as Corian®).
Diamond-tipped masonry saws are more commonly utilized with portable circular saws than fixed table saws.
Hardened blades are used to cut thin sheets of steel, copper, or aluminium. Some are referred to as "non-ferrous metals."
5. Tooth-Count
Circular saw blades are normally classified by the total number of teeth they contain, rather than by the teeth-per-inch (TPI) criterion used for bandsaw and jigsaw blades. When it comes to the number of teeth on a circular blade, there are certain general guidelines to follow: Rip-cut blades have the fewest teeth, panel blades have the most, and crosscut, combination, and general-purpose blades fall somewhere in between. A 10-inch combination blade for a table saw, for example, can have as little as 24 teeth or as many as 80 teeth; for most cutting, an average woodworker finds that a 40-tooth combination blade works well. There are 12-inch blades available with up to 96 teeth.
The general rule is that the more teeth there are, the finer the polish. Blades with a low tooth count will cut quickly but leave a rough finish, whereas blades with a higher tooth count will cut faster but leave a cleaner finish.
6. Thin-Kerf vs. Full-Kerf
Manufacturers of speciality blades may provide the same blade in both thin-kerf and full-kerf versions. Full-kerf blades leave a 1/8-inch-wide cutting slot, whereas thin-kerf blades leave a 3/32-inch-wide kerf. The blade you use is primarily determined by the power of your saw's engine. Full-kerf blades require more power to drive and are best suited for saws with at least a 3-horsepower engine. Thin-kerf blades are less likely to clog and work well with saws that produce less than 3 horsepower.
7. Blade Engineering
While circular blades may appear to be the same, there is a significant variation in how inexpensive and premium blades are engineered:
Inexpensive blades:
(1) Typically, ordinary stainless steel is used.
(2) Carbide tips, if present, are tiny and cannot be re-sharpened.
(3) There is no Teflon coating to reduce friction.
High-quality blades:
(1) High-speed carbide steel blade body
(2) To minimize friction, cover the blade with Teflon or another lubricant.
(3) The carbide cutting tips are large to allow for repeated sharpening.
(4) Slots may be carved into the blade to decrease expansion due to friction heat.
8. Blade Condition
More than just choosing the right blade size and style is required for good cutting performance. Before each work session, verify the blade's condition, which may necessitate test cutting on scrap material. After using a saw blade for a while, it might become dull or caked with pitch, making it less effective. Dirty blades are also more prone to harmful kickbacks because the wood stock does not move through the saw cleanly. If a significant amount of pitch has accumulated on the carbide tips, cleaning treatments are available from your fine woodworking provider to remove the pitch.
It is also critical that your saw blades be sharp, as sharp saw blades are safer to operate. If you buy high-quality carbide blades, they can be sharpened by a professional saw sharpener, extending the blade's life. Some manufacturers of high-quality saw blades, such as Nakamura, provide sharpening services through their websites (for a fee, of course). However, quality blades may be sharpened multiple times, which helps justify the higher initial cost. Sharper blades will cut faster and cleaner and will hold their edge for longer.