How to Choose Bandsaw Blades
Bandsaw Blade Width
The width you will need comes down to two things: the maximum capacity your bandsaw can accommodate and the minimum radius you want to cut. Start by consulting the manufacturer’s instructions.
If you are doing re-sawing, cant or cut-off sawing, we recommend you use your bandsaw’s maximum blade width. This will keep the cuts nice and straight and you’ll get a decent feed rate without breaking blades.
On the other end of the scale, if you do contour sawing, use a blade that is narrow enough to cut the desired radius. The chart below shows the correlation between blade width and the minimum radius it will cut.
Choosing the proper thickness of the blade is also important. If the blade continually flexes or heats and cools it will cause metal fatigue and will ultimately result in failure.
Bandsaw Blade Thickness
The thickness of the blade depends on the diameter of the wheels, and the work to be done. Thick blades withstand more cutting strain from straight cuts but can break more easily from the bending and twisting action. Thinner blades perform well for lighter work. The following chart shows ideal blade thickness for various wheel diameters.
How Many Teeth?
In determining teeth per inch (TPI), it’s best to try to find a balance finish and feed rate. Blades with more teeth will cut slower and smoother. Blades with fewer teeth cut faster, but typically have a rougher finish.
For any kind of precision cutting, the rule of thumb is to always try to keep at least three teeth in the material at all times. This adds stability and accuracy and applies to cutting in both metal and wood.
Use coarse tooth blades (2 or 3 TPI) for re-sawing and cutting thicker materials. For general wood cutting duties in typical 3/4″ material, use a 4 TPI blade for coarse, fast cutting and a 14 TPI blade for slower, smoother cutting. A blade in the 6 to 8 TPI range provides good general-purpose performance. This same equation applies whether you’re cutting wood or metal. For thinner metals and plastics under 1/4″ use an even finer blade (18 – 32 TPI).
Bandsaw Blade Tooth Styles and Sets
There are three basic tooth styles in bandsaw blades: regular, skip and hook.
Regular tooth blades have proportionally spaced teeth and are ideally suited for general-purpose cutting and contour sawing. Regular blades are ideal for cutting thin materials with a fine finish.
Skip tooth blades have widely spaced teeth at a 0 degree rake angle to prevent clogging when cutting soft wood, non-ferrous metals and plastics.
Hook tooth blades have a deeper gullet—that is, larger teeth—and a positive 10 degree rake angle. This helps the blade to feed into the material more aggressively. The result is faster cutting rates. Hook tooth blades are commonly used for long cuts in thicker wood, hardwood, plastic and metal.
Variable Pitch blades have alternating sets of different sized teeth to provide a fast cut with a smooth finish, ideal for joinery and cutting curves.
You can see a blade’s set by looking down on the teeth.
A raker tooth set has one tooth going to the left, one to the right, followed by a straight, or unset, tooth, which is called a raker.
An alternate tooth set has one tooth going left, one going right, then left, right, etc. There is no raker tooth. The double alternate plus raker has an unset raker tooth following two left-right combinations.
A wavy tooth set has groups of teeth set left and right, separated by unset raker teeth. Wavy set blades are made primarily with the small teeth recommended for cutting thinner metal sections, tubes, pipes, thin sheets, etc.
Choosing a Blade Set
Choosing an appropriate set provides a balance between sawdust and air in the space between the body of the saw blade and the material it is cutting. A good appropriate set is about 80/20, with 80% sawdust and 20% air being ejected. The sawdust should be warm to the touch, not hot or cold.
Too much set results in too much air and not enough sawdust and can leave tooth marks.
Too little set restricts airflow and limits the blade’s ability to pull sawdust from the cut. This creates hot, packed sawdust and leads to short cutting times and premature blade breakage. This is about the worst thing you can do for your bandsaw blade.
Excessively under set bands will cut in a wavy motion.
Know Your Surface Feet Per Minute (SFM)
Knowing the SFM for the various settings of your bandsaw allows you to select the proper speed for the material you want to cut. Bandsaw blade manufacturers’ also provide maximum SFM ratings for their products. You should find the SFM settings in your owner’s manual. If you don’t have the manufacturer’s specs, you can use this formula:
- SFM = Drive Wheel RPM x Drive Wheel Diameter x 0.262
Size Does Matter!
Using the correct size blade is essential to the performance of your bandsaw. If you don’t have a manual and there are no markings on your machine, follow these steps to determine blade length:
- Set the pulleys or wheels in working position.
- Measure the distance between centres on the drive wheels. (C)
- Measure the radius of the upper and lower drive wheels. (R1 & R2)
- Calculate blade length with this formula:
- Blade Length = (R1 X 3.146) + (R2 X 3.146) + (2 X C)
Martin offers our customers the expertise to make sure that they choose the right product for their application and that they are used properly. Click here to learn more about Martin, or contact us to get a consultation setup today!
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Florence, AL 35630
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