Quite frankly, you will find the use of scoring blade invaluable if you want to get a clean cut on the bottom side of plywood or any composite material you want to cut. It helps prevent tear-out on the material, allowing you to produce a splinter-free cut. Moreover, the scoring blade comes in front of the larger main blade and hits the wood piece first.
Yet, you may be asking whether it is really necessary to use a scoring blade? Well, I think it is needed if you want to get a clean cut on a composite material.
The scoring blade is an additional blade in front of your main blade. It cuts a kerf that is a bit wider than that of the main blade. Besides, it is set in such a way so that its teeth are backward-pointing. It also turns in the opposite direction relative to that of the main blade. Moreover, it has a shallow setting, enough to score or nick the plywood’s bottom surface.
How Does A Scoring Saw Blade Work?
When working with bonded materials or wood composite, your table saw blades might find it hard to cut quickly into those materials. In several instances, the regular table saw does not work well in such materials and ends up chipping the material’s underside.
Hence, you need to score the materials’ edges to make it easy for the main blade to cut. For this purpose, you need to use a scoring blade. This blade can make it easy for the main blade to cut clean through such composite or bonded materials.
The scoring saw comes with two blades: the primary blade or main blade and the scoring blade. In this type of saw, the main blade cuts from the top while the smaller blade nicks the bottom. The smaller blade needs to cut a groove or score to make it easy for the main blade to deal with the material. The main blade is then required to cut through the panels’ single layers.
The real reason why there is a need for a scoring blade lies in how the main blade’s teeth enter the material. The teeth move downward. This way of hitting the workpiece can produce a clean cut. Yet, if the material is a composite material made of various layers, the other side of the panel may exhibit blowouts or chips.
Thus, to make a clean and nice cut, you will need a scoring blade. The scoring blade is there to cut through the material’s underside. It can cut to about 1 mm on the lower face of the material while rotating upward. Scoring the material prevents chipping. The upper face of the material remains uncut because it remains untouched by the scoring blade.
Advantages of Using a Scoring Blade
When it comes to using a scoring blade, you will quickly see that the main advantage of having a scoring blade in your table saw setup is the prevention of tear-out and chipping. Plywood tear-out can be hard to deal with and devastating. However, with the scoring blade, you can cut cleanly the outer fibers of the workpiece.
In this way, the main blade’s teeth will strike the outer fibers at a very steep angle, pushing them sideways instead of pushing them downward. Since the scoring blade comes with pointed teeth, it produces a scoring effect similar to the scoring of the fibers using a utility knife. Moreover, you can score both sides using the scoring blade. In doing so, you will get a crisp cut on both sides.
Most table saws come with around 40 or 50 teeth. Such blades can cut across or with the grains, and as long as these blades are kept clean, sharp, and of good quality, you can cut well around 90% of your solid wood materials.
Yet, when cutting across the grain of composite materials like plywood, you will notice that the plywood grains, for example, crisscross each other. This is because each layer comes with grains that go in the opposite directions.
On the other hand, the outer layer does have a distinct grain pattern, and its fibers will splinter when you cut with the standard saw blade with 40 teeth or low tooth count. You may not think about this much, but plywood is best cut with blades with high teeth count. Moreover, you can cut the plywood best with the help of a scoring blade.
Disadvantages of Using a Scoring Blade
Despite the obvious advantages afforded by the scoring blade when cutting through the plywood and other bonded materials, its use is not without drawbacks. For example, it may work well for straight cuts. But it becomes valueless when doing beveled cuts. Hence, when engaged in beveled cuts, you need to lower the scoring blade to get it out of the way.
The reason is that when beveling, the main blade must be raised while the scoring blade could barely hit the material. Hence, it will only mess the cut up instead of helping you produce a nice and clean cut in such an instance.
Another possible drawback of the use of scoring blades is the learning curve relative to its use. Since the scoring blade rotates in the opposite direction to the main blade, it pulls the material upward while the main blade pulls the material downward. You may find this a bit confusing and disconcerting if you are not used to it. Moreover, if it is set higher, it can jerk the wood piece upward or toward you, which can be dangerous.
Lastly, you need to sharpen the scoring blade—a work that could add up to the works you already have in your workshop. The scoring blade seems to last longer and doesn’t need much sharpening. Yet, you will not use only one main blade. More often, you will change the main blade. Moreover, every time you sharpen the primary blade, you also reduce its width a bit. So, you need to make an adjustment again.
If you change the main and keep the scoring set on, you need to adjust the scoring blade relative to the new blade. In such a case, I think it is better to have a set consisting of the main and scoring blade, for you may save more time in buying a new set than in sharpening both blades.
Is Having an Extra Blade of Scoring Blade Safe?
Theoretically, it is dangerous to have another blade that counter rotates to the main blade because it can pull forward the stock, which may be quite risky to the operator. Nevertheless, since the scoring blade only nicks the material, it is quite manageable to have.
Moreover, the workpiece’s weight is sufficient to keep this blade from hurling the workpiece forward. The scoring blade can also help in hogging the particle board’s sensitive coating to pre-score the main blade’s cutting edges.
The scoring blade is around 0.1 to 0.2-mm broader than that of the main blade. With the scoring blade’s pre-scoring works, the main saw blade will never have a hard time cutting through the materials. Moreover, it works clockwise and doesn’t cut down, and it has a high speed.
You might have been impressed by how fine and clean, professional woodworkers cut composite materials like plywood, and you want to know their secret. Of course, their secret lies in having an additional smaller blade called scoring blade in their setup. This scoring blade cuts a kerf that lets the main blade deal with the plywood underside with ease.
As an aspiring woodworker or a beginner woodworker, it will be useful to consider using a scoring blade. You can achieve a splinter-free cut if you have a scoring blade to complement your main blade. The scoring blade can leave a 1.5-mm to 2-mm deep footprint in your workpiece, allowing the main blade to proceed well with ease in dividing the workpiece. It can also score the top side of a coated panel.