Basic bandsaw blade terminology for blade maintenance

Most sawyers focus on milling, building and thinking up their next project. But knowing your blades and keeping them in prime shape is important to continue working on your innovative new ideas.  

Maybe you are fresh to your Woodland Mills Sawmill or you are an experienced sawyer who wants to know more to prepare for using your Woodland Mills Bandsaw Blade Sharpener. Either way, here is a brief explainer showing the components of a blade to keep them ready for the next job:

How a bandsaw blade works

In a horizontal bandsaw mill, a flexible band saw blade is run between two band wheels on a head assembly. That head is then pushed down a track and into the log which rests on the track bed.

As the blade is pushed into the log, the rapidly-moving tooth tip penetrates the wood, removing a small amount of material and turning the solid wood into sawdust. At full speed, the blade teeth creates a cutting edge which slices into the log.

It's important to know how your bandsaw blade works, and the components of your carbon steel blades, so when you're sharpening them you know what each part of the blade is contributing and why it's important to care for it.

Tooth Set

Sawmill blade tooth geometry follows a particular “set” pattern where the first tooth is straight (rake
tooth), the second tooth is set up, and the third tooth is set down. This three-tooth pattern
repeats throughout the entire length of the saw blade. That means that the cutting edges of the teeth are wider than the blade itself (see the impact below in the Kerf section), which assists when cutting into a log. You can use your Woodland Mills Blade Tooth Setter to restore your Set back to its factory default to extend the life of your blade or to a custom Set. 

Width

Your blade width is measured from the bottom of the blade up to the tip of the tooth. The RS30 PRO Bandsaw Blade Sharpener is compatible with 1 – 1.5” wide blades and the RS8 Bandsaw Blade Sharpener are compatible with blades which are 1 – 1.25” wide. This measurement is important when it comes to buying new blades, so you know what size to get that fit on your sawmill's bandwheels.

Kerf

This refers to the measurement of the narrow channel cut into the wood by the blade, the width of which is defined by the distance between your bent Set Teeth. Material milled by the kerf is turned into sawdust, so it's important that you know how much material is being lost if you're making precise and accurate cuts.

Pitch

The Teeth Per Inch, or Tooth Pitch, means the distance between the tips of each of your sawblade’s teeth.  The distance is shorter for teeth on blades designed for hardwoods while it's farther on ones meant for general softwoods. Bigger blade pitches like 7/8 help reduce sap build up and improve sawdust ejection, leaving faster feed rates for softwood logs. Smaller pitches like 3/4 are reserved for smoother, stable cuts for hardwoods, that require more cutting points for greater grain density.

Face

The front of the sawblade tooth is known as the face. When a blade is being maintained, the sharpener will grind down the face and clean the Gullet to provide new life to your blade. Sharpening only removes few thousandths of an inch from the tooth face.

Gullet

The space between each tooth is known as a Gullet, the depth of which is measured from the lowest point of the valley between the teeth to the tip of the tooth. As you mill the gullet is responsible for removing sawdust while the teeth cut in the wood. When sharpening, this area is cleaned by the grinding wheel to remove microcracks, which if not removed can shorten the life of the blade.

Back Angle

Additionally referred to as the Relief Angle, this is the angle down the back of the tooth. This does not need to be sharpened, since it's not a cutting edge.

Hook Angle

Also known as the Rake, this is the angle of the front face of the tooth perpendicular to the length of the blade. This Hook Angle may need to vary depending on the species of wood you are sawing or whether your wood is frozen. Woodland Mills' blades for general softwoods have 10° hook angle while blades for hardwoods or frozen logs use 7° angle. Steeper angles like 10° have greater 'biting' effects for speed, while lesser angles like 7° account for added tooth stability that keeps cuts smoother.