What is the Gullet of a Saw Blade?

In this blog post, you’ll read:The gullet is the rounded gap, cut into the blade plate, between the teeth. This gap is intended to bring waste, such as sawdust and chips, away from clogging the blade. On the saw blade, the size of the gullets is closely related to the feed-rate factor. There are more teeth, and therefore narrower gullets in Crosscut saw blades, while the heavy-duty and rip saw blades have wider gaps between each tooth to easily extract the sawdust.

The gullet is the rounded gap, cut into the blade plate, between the teeth. This gap is intended to bring waste, such as sawdust and chips, away from clogging the blade. On the saw blade, the size of the gullets is closely related to the feed-rate factor. There are more teeth, and therefore narrower gullets in Crosscut saw blades, while the heavy-duty and rip saw blades have wider gaps between each tooth to easily extract the sawdust.

In order to hold all the sawdust made, the gullet must be broad enough. A full gullet indicates that no more cutting can be done; slower than usual feed speeds will have to be used, plus the blade can vibrate intensely. When making deep cuts, larger gullets are needed.

Functions of Gullet

The gullet is essential in performing various functions. The gullet is very important in preventing the blade from overheating and burning. It also plays a vital role in removing the extra sawdust and thus keeping the blade away from overheating and jamming. The following are some critical functions that the gullet is responsible for.

Against heat

To prevent blade overheating and burning of the material being cut, the gullet is essential. Sawdust gets stuck without a considerable enough gullet, sticking to the blade and increasing friction, creating excess heat. As sawdust burns much easier than solid wood, it is actually probable to start a fire this way (although uncommon). The blade will begin to warp with sufficient overheating, raising the thickness of the saw and eventually damaging the blade.

It is not suggested to try and rip with crosscut blades. On the crosscut blade, the smaller, more regular teeth are followed by smaller gullets that do not have sufficient ability to take away the more significant number of chips and sawdust. Crosscut blades cut slower and have sufficient time for the waste material to be drawn out so that the big gullets are not needed. Because of the accumulation of sawdust and chips, even though you could force the wood through the saw blade, it would jam.

Against sawdust

For both ripping and crosscuts, combined circular saw blades are used. Saw blades tend to collect too much sawdust in the saw kerf if used for ripping. Some combination circular saw blades overcome this chip buildup problem by skipping teeth and inserting after every five teeth or so an extra deep gullet. A deep gullet between the sawtooth profile groups allows a place to remove the excess sawdust from the saw kerf, thereby reducing the issue of overheating.

Softwoods prefer to leave packed chips that are larger and looser than hardwoods. So with softwoods, this issue of sawdust accumulation can be worse in the gullet. The problem is only increased if you are cutting moist wood, as the dampness in the wood will help it clump together instead of dropping away from the gullet. As the blade gets clogged more and more, the temperature increases; carpenter can only find it when the circular saw begins to strain or the blade plate begins to bend.

The explanation why the opposite case is an apparent error and is less likely to happen: when the ripping blade is accidentally used for crosscuts, the fact that the rip saw blade allows untidy cut with a lot of waste and big splinters of wood prohibits woodcutters from using it.

Against non-ferrous metals

Aluminum and brass have a tendency to stick to the blade, both of which can be cut with a carbide-tipped circular saw blade. They’ll stick to the face of your teeth more than anything else. These materials can easily clog up the gullet in this process, preventing the blade from sticking. Stop periodically to check the blade for material sticking to it while you are cutting any of these materials.

Blades with large gullets

While saw blades are not graded by the size of their gullets, when inspecting the blade, this is something that is immediately evident. The blade developers consider the intended usage of the saw blade, guaranteeing that they provide a big enough gullet for the defined use. However, the gullet may not be sufficient when the blade is used for purposes other than the aim, particularly when a crosscut blade is used for ripping.

Blade Terminology

When discussing cutting issues, a good understanding of blade terms will help prevent misunderstanding. Some terms that are necessary to comprehend are below.

Blade back

The upper surface of the blade plate is called the blade back. It does not include the teeth.

Blade thickness

The dimension from side to side on the blade is the thickness of the blade.

Bevel

Teeth can have a single bevel, two or no bevels at all. Bevel types may vary from tooth to tooth on a defined blade. The bevel is what gives a blade its unique cutting pattern.

Width

As measured from the tip of the tooth to the back of the band, a saw blade’s nominal dimension is the width.

Set

To allow clearance of the back of the blade through the cut, the bending of teeth to the right or left is called set.

Kerf

Kerf is the Amount of material removed by the cut of the blade.

Tooth Pitch

Tooth pitch is the distance from one tooth’s tip to the next tooth’s tip.

TPI (teeth per inch)

TPI is the number of teeth per inch, as measured from gullet to gullet.

Gullet

The gullet is the curved area at the tooth’s base. From the tooth tip to the bottom of the gullet is the diameter of the gullet. To hold all the sawdust made and to prevent the blade from overheating, the gullet must be broad enough.

Tooth face

Tooth face is the tooth surface on which the chip is built.

Tooth rake angle

Tooth rake angle is the angle of the tooth face determined with respect to a line perpendicular to the cutting direction of the saw.

References
1.http://circularsawblade.net/crosscut
2.http://circularsawblade.net/rip-cut
3.http://circularsawblade.net/combination
4.http://circularsawblade.net/non-ferrous-metals-plastics-glass