“COMMON SENSE” SAWING

Today’s saw blades are made from the best steels available and are manufactured on the latest and best equipment attainable. All blade manufacturers produce a product that will perform satisfactorily given the opportunity. Modern cutting tools, including blades, are generally of consistent quality – more so than the myriad of materials that are being cut, such as steels of all varieties, plastics, wood, etc.

It is logical and common sense to realize this important fact: There are far more inconsistencies in the materials being cut, machine conditions, improper applications and human input than in the cutting tools that are actually expected to neutralize and abolish these many inconsistencies.

Cutting with bandsaw blades present some uncommon or unique situations when you consider these facts:

A bandsaw blade is a somewhat unstable tool due to its very nature.

It has to be relatively thin and narrow in order for it to flex, bend or twist as it does on any common saw machine. This, coupled with blade tension (to make it cut square and track properly on the saw wheels) and cutting forces that are generated while the saw teeth bite into the work piece and pull out chips, create tremendous forces that try to rip the blade in two or break out or strip the saw teeth.

These forces are severe enough when everything is in order, including speeds or velocity of the band, and feed pressure – the force at which the blade is fed into the work piece or conversely, the work piece is fed through, or into the blade (such as on a vertical, upright saw).

If improper speeds or feeds are used while cutting, problems are multiplied several times, resulting in much reduced blade life or no life at all due to excessive heat and chip load, deformation of the back of the blade, crooked or washboard type cuts and broken, flattened and stripped teeth. All of this can occur before the blade actually surrenders and gives up by cracking, fracturing and breaking.

Another unique fact about band sawing: There is not another cutting tool that operates under the same circumstances as bandsaw blades.

Again, common sense tells us, if we allow it to – that a bandsaw blade is in almost constant contact with either moving or stationary machine components that are usually made from steel or carbide.

These components consist of the band carrier wheels, both drive and idler wheels, and the bandsaw blade guides, usually roller bearing type or solid carbide top and side guides. Metal against metal. This fact in itself is disturbing as well as unique. The blade is confronted with rubbing, scraping, flexing, bending and twisting constantly as it travels around and around the wheels and then twists into the first guide, then into and through the work piece, then through the second guide and up onto and around the wheels, again and again.