A WARNING: We manufacture a very special series of LOW TENSION, HIGH DUCTILE, SILICON STEEL BAND SAW BLADES for wood cutters and sawyers. At the present time from 1/8″ through 2″. Our blades run purposely with 35% to 50% less tension than our competitors carbon blades. Being very stable at low tension, over 70% of the rotation fatigue effect is eliminated, increasing blade body life(flex life) dramatically, and 20% LESS HORSEPOWER IS REQUIRED. Please read “THE 6 RULES OF SAWING” for proper tensioning.
B. Check your tires and guides. Our Silicon Steel Blades like all other narrow carbon band saw blades 2″ and under, run best on a cushion of urethane or rubber. The shock absorbing quality of resilient tires around metal band saw wheels, extend blade body life dramatically. Modern band saw wheels have a crown machined across the face of the metal wheel. This crown can be as little as .010 thousandths, for tracking 3/4″ and narrower bands, or as much as .030 thousandths for tracking 2″ bands. This crown causes the effect of self-tracking. This is the same principle used for tracking sanding belts on a belt sander. Age, over tensioning and not detensioning the blade after use, compress and flatten the crown out of the tire. This compression will also make the tires hard and brittle. Old tires cause band breakage!
How do you know when the time has come to replace your tires? Simply by looking at them. When the crown in the tire has flattened out equal to 1/2″ the width of the blade you are using, the time has come to replace them. At this point the tension you apply must increase in order to stabilize the blade.
C. Always try to keep 6 to 8 teeth in the cut at all times; this is for metal or wood cutting. It will give you stability and more of an accurate cut when scrolling or straight-line cutting. This rule does not apply when resawing or milling logs and cants. With a constant pitch, the appropriate set of the teeth and the articulation of the hook angle become the most important factors when using 1 1/4″ to 2″ resharpenable and resettable blades. Please read “THE SIX RULES OF SAWING”.
D. Fatigue Ratio of a Band Saw Blade: The stress being applied to the blade body; due to wheel diameter, blade length, thickness, speed (surface feet per minute-S.F.P.M.) and tension.
Blade Body life diminishes rapidly when put into any one or more of the stressful situations listed above. You will find some stress built into the band saw by the manufacturer, either by mistake or by design.
Band Saw Mills running 1 1/4″ and larger blades by .042 thick on wheel diameters smaller than 19″ will also experience decreased blade body life (flex life) due to the smaller wheels. The blade as it travels around the wheel is compressed on the inside of the body, which is closest to the wheel and stretched on the outside of the body. Blades are designed to absorb repeated compression and expansion of the body as long as the compression and expansion does not exceed the steels capabilities. Small band saw wheels exceed the steels capabilities. Two wheel machines, with smaller than 14″ wheels, using 1/8″ to 3/4″ blades will encounter 20% to 50% less blade life. With machines 14″ and larger, you will see blade life increase proportionally. You will encounter decreased blade life with any three-wheel band saw even if the wheels are larger than 14″.
E. Examples of optimum Surface Feet Per Minute on vertical band saws running 1/8″ to 1″ wide blades. It is not considered wise to exceed these values.
|Wheel Diameter||S.F.P.M.||Wheel Diameter||S.F.P.M.|
|12″||= 2,800||24″||= 4,000|
|14″||= 3,300||26″||= 4,000|
|16″||= 3,800||28″||= 4,000|
|18″||= 4,000||30″||= 4,000|
|20″||= 4,000||36″||= 4,000|
As you exceed the S.F.P.M. for a specific wheel diameter, you greatly increase the centrifugal force applied to the body of the blade traveling around the two wheels. This causes you to over-tension your blades in order to make them run stable. This WILL cause premature and excessive blade breakage. There is also a minimum speed you should run a band saw blade. (EXAMPLE: Timber Wolf® band SAW blades should not run under 2,400 S.F.P.M. and Timber Wolf® band MILL blades should not be run under 4,000 S.F.P.M.)
Example of Surface Feet Per Minute on a band mill or power feed resaw running 1″ to 2″ wide mill blades:
|Blade Width||Tooth Pitch||Gullet Depth||S.F.P.M.|
|1″ & 1 1/4″||3/4″||1/4″||5,300|
|1 1/4″ & 1 1/2″||7/8″||9/32″||5,800|
Formula To Find S.F.P.M. Is: Motor RPM X Motor Pulley Diameter / Driven Pulley Diameter X Band Saw Wheel Diameter X 3.1416 / 12 = S.F.P.M