In order to get the best quality and efficiency from your bandsaw, you need to use the proper wood cutting band saw blade. There is no one version that will work in all instances since the bandsaw is so versatile and can make many different types of cuts. The cut you are making -  resawing, ripping, or a curve – will determine what type you will want to use. Often the saw blade that comes with your machine will not be a premium model and this will be one of first upgrades you will want to make. When you shop for bandsaw blades there are numerous factors to consider including length, width, thickness, material/constuction, pitch, tooth style, and tooth set. We will look into these in more depth later in the article, but first lets take a look at a cross section of a blade and define some of the terminology associated with it.

• Guage- The thickness of the blade.
• Width – The nominal dimension of a saw blade as measured from the tip of the tooth to the back of the band.
• Set – The bending of the teeth to right or left to allow clearance of the back through the cut.
• Tooth – The cutting portion of a saw blade.
• Tooth Tip – The cutting edge of the saw tooth.
• Tooth Face – The surface of the tooth on which the chip is formed.
• Tooth Back – The surface of the tooth opposite to the tooth face.
• Tooth Spacing - The distance from the tip of one tooth to the tip of the next tooth.
• Pitch - The number of teeth per inch (TPI).
• Gullet – The curved area between two band saw teeth into which the chip curls.
• Gullet Depth – The distance from the tooth tip to the bottom of the gullet.
• Tooth Rake Angle – The angle of the tooth face measured with respect to a line perpendicular to the cutting direction of the saw.
• Kerf – The width of the slot made by a band saw as it cuts.

Length

The length of the blade will be determined by the size of band saw you are putting it on. Stick with the manufacturer recommendations for the proper length for your machine. The key to making it work properly is to ensure that the correct amount of tension is applied, which can be difficult if the band is either too short or too long. The most common sizes are 93 1/2″ and 105″, which are the standard lengths on 14-inch bandsaws and 14-inch models with riser blocks installed on the machine.

Width

Blade width is measured from the tips of the teeth to the back edge of the blade as shown at right. Again stick with the manufacturer guidelines for your bandsaw as to the minimum and maximum widths allowed.

For re-sawing or making straight cuts the blade should be as wide as the machine will allow. The wider the band is the faster you can feed the material and also the straighter your cut will be.

For cutting curves the blade should be the widest your machine allows that still allows you to cut the desired shape or radius. The band width determines the minimum radius which it can saw. For example the smallest radius a 1/4″ blade width can cut is 5/8″. (See chart at right for widths and their associated radius)

Thickness

Referred to as gauge, it is measured as the thickness of the backing material on the blade. Gauges normally range from about .014″ – .063″. The thicker the band the stronger its beam strength is, but also the more force that is needed to apply the proper tension on it.

Each revolution on the band saw flexes the blade and causes the metal to fatigue and eventually fail, or in other words break. Thick blades can withstand more strain, but will also break more easily from fatigue, especially when being run on small diameter wheels. Therefore stick with thinner bands whenever you can, especially for light work.

Material / Construction

Bandsaw blades can be generally be classified into 5 different types of blades based on the way they were constructed. Those being constant hardness, flex-back, hard-back, bi-metal, and carbide tipped. Each type is made from steel of different characteristics. Then on some the teeth are hardened or even welded onto the backing material. The teeth are measured for hardness on the Rockwell C scale (Rc), where a 1 point increase on the scale doubles the abrasion resistence of the material.

Constant hardness blades are usually made from spring steel and have no other treatments applied to them. They generally have a 36-45 Rc hardness rating. These are not recommended for regular use.

Flex-back blades are made from high carbon steel that that then have the teeth hardened after they are ground. The teeth on this blade have about a 63-65 Rc which makes it more durable and can withstand the heat and abrasion of resawing. They are called flex-back because the backing material is still soft which allows it to reduce fatigue on small wheel band saws.

Hard-back blades are also made from high carbon steel, but these have the teeth and also the back hardened to around 63-65 Rc. These should not be used on small diameter wheels because they will fatigue quicker than flex-back types. They are primarily used in a production environment where they provide a stiffer beam for resawing thick stock.

Bi-Metal blades are harder, about 65-66 Rc, and more heat resistant than high carbon steel blades. The teeth tips are made of a high speed steel that is electron beam welded to a high strength spring steel alloy backing material. Bimetal blades stay sharper much longer, but require more tension than carbon steel blades, about 20,000-25,000 PSI instead of 15,000.

Carbide tipped blades are bands that have solid carbide teeth, Rc 68, welded to a high strength steel alloy backing material. This results in a fatigue resistant blade which performs well cutting abrasive materials such as stainless steels, nickel, and tropical hardwoods. They require a tension of about 25,000 PSI. They are premium blades that will last 3-4 times longer than bi-metal versions. A slightly different variation is the carbide grit blade in which a tungsten carbide particle grit is metallurgically bonded to the band. This blade performs well cutting abrasive and difficult to cut materials such as fiberglass, composite material, and even steel-belted tires.

You may also see blades referred to as thin or narrow kerf blades. This does not really refer to the material, but rather the fact that it leaves a kerf as small as 1/32″. They are usually made with spring steel, or perhaps a more exotic alloy, with the cutting edges of the teeth hardened. These are the preferred blade for resawing expensive wood because the thin kerf results in increased yield from the stock you are using. They should not be used on green wood or for cutting curves.

Pitch

Pitch is the number of teeth per inch (TPI) on a band saw blade. The pitch is important in determining the finish and feed rate of your stock. The more TPI, the smoother the finish on your material, but also the slower the cut will be. Less TPI will result in a rougher finish, but will allow a faster feed rate. A good rule to remember is to have at least 3 teeth and no more than 12 teeth in the work piece. For example a 1″ stock shoud be cut with a band that has at lease 3 TPI. (For the minimum material thickness that a certain TPI can cut, see chart to the right.)

In general stick with a coarse tooth blade (2 – 3 TPI) when resawing, and a finer model (18-32 TPI) for thinner materials including metals and plastics under 1/4″.  

Tooth Style / Form

There are four different forms of teeth styles – regular tooth, skip tooth, hook tooth, and variable tooth – that band saw blades may have.

Regular tooth, or standard tooth, has evenly spaced teeth with 0 degree rake. Ideally suited for both cut-off and contour sawing of most materials and for cutting thin materials where a fine cut is required as they leave the smoothest finish. They are not recommended for long resawing because the gullets can fill up with sawdust and create a lot of friction and heat.

The skip tooth style is virtually the same as regular, except that every other tooth is missing. This leaves a large gullet which tends to break up the chips and prevents clogging the blade when cutting softer materials. 

The hook tooth style has a positive 10° rake angle, widely spaced teeth, and deep gullets which helps it dig in and take a good cut while the gullets tend to curl the chips. This style is recommended for long cuts in harder and thicker woods. It also leaves a rougher finish than regular or skip tooth.

Variable tooth style has teeth with varying set angles, gullet depths, and possibly pitch. The advantage they have is that they reduce vibration, which means they are smoother and much quieter. They work work well for cut-off sawing and contouring.

Tooth Set

The teeth on bandsaw blades are bent out to the left or right in a pattern and is referred to as tooth set. Tooth set is used to widen the cut and prevent pinching of the saw blade. There are four different types of set – raker, modified raker or vari-raker, alternate, and wavy.

The raker set consists of one tooth to the left, one to the right and one tooth, the raker, is unset. It is used for contour cutting and resawing on vertical band machines.

In a modified raker set, or vari-raker set, the tooth pattern is left, right, left, right, and straight. This is an excellent choice for cutting wood on any vertical stationary band saw. They might not be available for every tooth form and blade type.

The alternate set has teeth that are offset every other tooth to the left or right. These provide faster, smoother cuts.

The wavy set pattern has groups of teeth set to the left and to the right, separated by unset raker teeth. They usually have small teeth and are used primarily for cutting thinner types of metal.