While there is a wide variety of styles and types of band saw blades, choosing the correct one doesn't need to be a daunting experience. This guide is intended to assist in you the selection of a band saw blade, as well as explain some of the related terminology and the proper break-in procedure for new blades. Here are some points to consider when selecting a blade.
Band Saw Considerations
The first thing you need to know is the band saw blade length. Band saws have either a single specific blade length or a range of blade sizes that can be used with each saw, and this information should be readily available in the saw's user manual. If you can’t locate a blade size, there are a couple of ways to measure for blade length. If you have an old blade, measure its entire length (end to end if it’s broken, or all the way around the loop if it’s still intact). Another option is to use a piece of string or similar material and measure the same way you would with an old blade.
Next, consider the application and what you'll be cutting with the blade. Will it be wood, metal, stainless steel, thin metal, plastic, etc.? Knowing the application and the material being cut will help in determining if you need a basic hardback or flex-back blade, or possibly a bimetal blade. You'll also want to consider how often the blade will be used and whether it's for repetitive production cutting, or just occasional or general-purpose use.
Teeth Per Inch (TPI) is another important factor to consider. Measured from gullet to gullet, the thinner the material to be cut, the more teeth per inch you'll want to have. A general rule of thumb is that there should be around 4 to 6 teeth in the material at any one time. For example, a workpiece that is ½" thick would do well with a blade that has 8 to 12 teeth per inch. While some blades have a set number of teeth per inch (6, 10, 14, etc.), others, called variable tooth blades, will alternate the number of teeth every other inch. A 10/14 TPI blade will have 10 teeth in one inch, then 14 teeth in the next inch and will repeat this the length of the blade. Variable tooth blades offer flexibility when materials of different thicknesses will be cut.
Band saw blades are available in a variety of widths, so it’s also important to know the capability of your saw relative to width. Blade width is measured from the tip of the teeth to the back of the blade.
Finally, there is blade thickness, which is measured from side-to-side on the cross-section of the blade. Thicknesses can range from around 0.020" to 0.035" for blades up to 11 to 12 feet long, while larger blades can approach 0.063" or more in thickness.
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Types of Blades
Carbon Flex-Back Blades: Made of high-carbon steel with hardened teeth. Used on wood, plastic, cork, composite board, plywood, aluminum, and nonferrous metals.
Carbon Hardback Blades: General-purpose blades that are stiffer than flex-back for straighter cuts, and will accept heavier feed pressures. Useful for short production runs and maintenance cutting of low-alloy ferrous metals, nonferrous metal, wood, plastic, cork, composite board, and plywood.
Bimetal Blades: Used for cutting structural steels, stainless steel, tool steel, castings, and nonferrous metals. Bimetal blades are more of a “family” of blades rather than one particular type. Blade manufacturers will have a number of different product lines under this heading, based on the types of metal to be cut (stainless steel, structural, tool steel, etc.) and the frequency of the operation (production, short production, maintenance/occasional).
The use of the correct lubricant is also important to consider with any cutting or drilling operation, particularly with metals. If your band saw does not have a lubrication system, a cutting oil stick is an option to consider.
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Blade Break-in Procedure
To achieve the best performance and service life from a blade, new blades need to be broken in properly. Here's what you should do.
- Select the proper band speed for the material being cut.
- Reduce the feed rate to 20% - 50% of normal. Softer materials need to have a larger feed-rate reduction than harder materials.
- Begin the first cut at the reduced rate and make sure the teeth are forming a chip. Small adjustments to the band speed may be needed if excessive noise and/or vibration occurs.
- During the first cut, increase the feed rate slightly after the blade is completely inside the workpiece.
- With each following cut, gradually increase the feed rate until the normal cutting rate is achieved.
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Product Compliance and Suitability
The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand and follow all manufacturer instructions.