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Bandsaw Blunders: How They Cut Blade Life

Ron Saxon and David Rosing of Simonds International reveal the top five sawing mistakes . . . and how to prevent them.

Posted: February 17, 2012

Cutting fluid is a critical part of the operation because it cools the blade, lubricates the teeth and washes away chips. Cutting fluid needs to be mixed with water, and it has its own special formula when used for sawing versus grinding and general machining. A richer cutting fluid mix should be used on bandsaws to better coat and lubricate the blade throughout the entire cut.
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Running a blade too fast or pushing material too hard can dull blades, break teeth, snap welds or crack the blade’s back edge. Chip welding can also be a problem. Know the material being cut and set the correct blade speed and cut rate. As a general rule, slow the blade for tough material and increase speed for softer material.
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Coolant should wash over the bandsaw blade as the blade enters and exits the cut. Coolant is recirculated and used continuously throughout the cutting process, but be sure to replace water that evaporates from the mixed solution.
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(4) DON’T BE TENSE
Hypertension isn’t good for anyone or anything, especially your bandsaw. Blades that are either too tense or too loose can cause problems, so make sure your blade is in a nice state of equilibrium. Most bandsaws work best with blade tension set to a minimum of 25,000 lb psi or a maximum of 32,000 lb psi. Anything less than 25,000 lb psi leads to poor beam strength, band fatigue or crooked cuts; more than 32,000 lb psi and you could break the band, crack the gullets or wear out machine bearings.

SOLUTION: Use a gauge to measure and properly set blade tension. If you don’t have a gauge or don’t know how to use it, give us a call and we’ll give you a free check and help you correctly set blade tension.

(5) APPLY THE BREAKS
Just like a new car or pair of shoes, you need to break in your blade. This will “hone” the teeth and extend blade life. Think of brand new blade teeth as freshly sharpened pencil tips. If you press down too hard on a pencil, you’ll break off its tip. A bandsaw tooth reacts the same way. Excessive feed pressure breaks pointed edges of bandsaw teeth.

SOLUTION: The best way to break in new bimetal blades is to reduce the normal feed rate by half during the break-in period. Band speed isn’t what breaks teeth during blade break-in; pressure from excessive feed rate is the most damaging dynamic. You will greatly improve the life of your blade if you take the time to break it in properly.

A Handy Formula for Breaking-In Bi-Metal Blades

Break-in rate: Fifty percent of recommended blade feed rate
Break-in formula: Multiply the recommended blade speed by 25 percent and cut that number of square inches.

Examples
Recommended blade feed rate: 200 fpm

Break in for: 50 sq in

Recommended blade feed rate: 100 fpm

Break-in for: 25 sq in

Once you approach the end of the break-in period, you can gradually bring your bandsaw feed rate back to normal. It is true that some blades are broken-in at the factory, but we recommend that you still use our break-in formula to make sure your blade is honed to perfection.

As the economy begins to improve, factories are under increasing pressure to perform. But even as you work hard to keep pace, there are no shortcuts to optimal performance – yours or the blade’s. Take time to get the information you need to do the job right, and cut out those mistakes.

Ron Saxon is a certified bandsaw operator and David Rosing is the technical manager of band saw products at Simonds International, 135 Intervale Road, PO Box 500, Fitchburg, MA 01420, 978-424-0100, Fax: 978-424-2212, www.neveryieldtosteel.com, www.simonds.cc.