Many woodworkers, especially hobbyists, carpenters and others who don’t require a high degree of precision, efficiency and smoothness of cut prefer to use combination saw blades. A combination circular saw blade is a design compromise between a rip cutting and crosscutting blade. It is designed to do both, by making design tradeoffs between the two. The main characteristic of this saw blade is the tooth pattern having around 60 ATBR teeth.
All Purpose and General Purpose Blades
“All purpose” or “general purpose” circular saw blades are not the same as combination blades. A combination blade is a design compromise between the strengths of the two types of blades, striving to strike a balance to create the most universally functional design. On the other hand, general purpose blades are usually just cheap blades, which ignore the best practices of design, trading them all of, in favor of producing an inexpensive saw blade. Combination ATBR saw blades should not be mistakenly confused with ATB or TCG blades, which are also suitable for ripping and cross-cutting through any type of wooden material, but offering different level of finish quality. Moreover, a combination saw blade is replacement for any other, if required blade is not in stock.
Ripping and Crosscutting
Although combination saw blades aren’t the best at either ripping or crosscutting, they do a reasonable job of both. They can be a good substitute for any other specialized blade. Their main sales point is eliminating the need to constantly switch between one blade and the other. This is very popular among amateur carpenters, who don’t expect the levels of precision and efficiency that the separate blades can provide. Read more about the differences in the rest of article.
These blades can be mounted in either table saws or radial arm saws. Application for single use, miter cuts and small amounts of lumber when there is no need to change the saw blade frequently is suggested, since they unite the best features of crosscut and rip cut saw blades. Combination is probably the most common type of blade to find mounted in miter saws, although ripping is essentially impossible on a miter saw.
A combination circular saw blade usually has between 50 and 72 teeth. The number of teeth is your choice because it varies from blade to blade, ranging from 40, 50, and 60 to 80. To provide the extra gullet space needed for ripping, they will group four or five teeth together, with smaller gullets. Then they will leave a gap for a larger gullet, looking as if a tooth was skipped over. A large gullet between these series separates dense groups of teeth and provides better chip clearance required for rip cuts. This compromise ATBR design helps ensure that the blade functions for both purposes. Alternating bevel teeth (ATB) are actually a feature of crosscutting blade, while the fourth or fifth FTG grinding tooth partly resembles the one used for ripping.
The teeth on a combination blade will either be ground to Alternate Top Bevel (ATB) or Alternate Top Bevel with Raker (ATBR). This allows the blade to provide fairly quick cutting for ripping, which helps to prevent splintering on cross cutting. When ground as an ATBR, the last tooth before the large gullet will be the “raker” or flat ground tooth. Using TCG as default sawtooth profile is not so common but allows cutting both softwood and hardwood, and plywood or laminates. It leaves fine cut surface and teeth are durable enough at the same time.
Selecting Blade and Differences
When selecting a combination blade, one must first decide whether their cutting will consist mostly of ripping or crosscutting. As all of these blades are design compromises, they will normally fall more to the ripping side or the crosscut side. Buying a combination blade which is more closely designed for the type of cutting which is usually done, generally provides the best series of options. For jobs that require more ripping take rather a combination saw blade with less, about 40 teeth. If you plan to do quick crosscutting, a combo blade with 80 teeth is recommended, especially if you buy blade with HiATB tooth form. Always pick an appropriate combination circular saw blade by looking at the frequency of use.
The biggest technology improvement when speaking about the durability of a saw blade was coating teeth with alloys that have high wear and heat resistance. It is important to buy combination blades which are coated to help prevent sticking. When using these blades for ripping, there is a higher risk of wood chips and sawdust sticking to the blade, than there is with a regular rip cut blade. A blade with a coated plate will normally resist this sticking better than a non-coated blade, helping clear the wood chips and keep the blade cool. Premium grade blades have C4 carbide coatings. Even Teflon (PTFE) is sometimes used, but it all depends from brand to brand. Buying a quality combo saw blade is important if you are planning not to change blade for a long period. These blades are more resistant than regular steel blades widely available on the market, regarding the fact that quality is followed by the price. However, deciding to set aside a little more money for a specialty blade will repay soon, you can expect an accurate cut, laser tested blade with a minimum amount of vibrations, and a lifetime warranty. An expensive blade cannot become dull or cracked easily when applied for long-term woodworking use. Corrosion resistance is a feature of an each saw blade, and the rust is, judging by the reviews, the smallest problem.
According to the manufacturers, circular saw blade breezes through the material much better if the plate is laser-cut. Woodcutting is possible with minimal vibrations and noise due to laser-cut reeds with copper plugs at the end. Features such as shoulders help to keep the straight cutting line, and an anti-kickback shoulder provides comfortable working conditions with these tools.