Recommendations How To Use Band Saw Blades

Sizes

Size of the band saw blade is chosen according to the machinery used and how the material is being cut.

Width of the band saw (H)

Width of the band saw is ussually defined in the operations manual of the machine. Width of the band saw may exceed by maximum 10 mm flywheel width of the machine. The wider the band saw is the longer tool life it will have respecting the condition above. You may choose then the widest blade respecting radius that will be cutting (see table below).

Recommended values of width of the band saw according to the minimum radius

Width of blade H (mm)	6	8	10	12	15	20	25	30	35	40	45	50
Minimum radius (mm)	15	25	40	60	100	140	180	300	400	500	600	700

For 40 – WM1 and WM2 band saw types the width of the band saw is defined by the machine producer and is derived from the flywheels used.

Thickness of the blade (S)

Thickness of the band saw blade must not exceed value S1 because the material of the band saw would experience excessive bending forces and thus it can be mechanically damaged. For flywheels with less then 350 mm of diameter always use maximum thickness of 0,7 mm, for flywheels smaller then 250 mm use band saw of maximum thickness of 0,5 mm.

Tooth pitch (T)

Tooth pitch is the distance between the tooth tips. Tooth pitch is chosen according to and respecting the height of the processed material, 3 to 5 teeth is recommened to be in cut at the same time.

Operating conditions

Maximum cutting speed of the band saw is defined by the machine producer. Usually the range is between 20 to 35 m/sec. General rule says the harder material is being processed the lower cutting speed is applied. Too small tooth pitch may cause jamming of the gullet space, the blade will not „enter“ into the cut smoothly and undercutting will occure, to the contrary too large tooth pitch will cause rough cutting surface and tearing of wood.

General rules for usage

1. Before you start cutting check if the band saw blade is properly sharpened, set and whether it is not damaged or heated up. Band saw heating can be recognized if blade has got purple color even after cooling.
2. Band saw blade must be properly tensioned. Please be aware not to tension the blade too much. This could cause breaking of the blade.
3. The tension of the band saw blade is measured by a special tool (tensiometer), maximum permissible values are specified by a producer of the machinery.
4. Guidance of blade and guiding wheels must be clean from chips and resin. Free play between guiding and band saw blade may be maximum 0,2mm. The distance between the top guidance from the cutting material should be as little as possible so that blade rigidity is as big as possible.
5. Hold the cutting material with both hands so that your body is not in the same axis as the cutting blade. Do not cut material using excessive force.
6. Start cutting after the proper cutting speed is achieved. Do not shorten or slow down the cutting period by friction of the blade against the side of material or slowing against cutting material.
7. While cutting off big dimensions it is important to use fixed guidance. At the end of cutting it is important to use holding device.
8. It is necessary to replace the band saw blade and leave it to rest (even if not dull) on time to maintain mechanical attributes of the band saw blade.
9. Do not let the band saw to heat up by any means. If this happens, set away the blade immediately, after cooling reset and resharpen it. You can also check the straightness. To prevent heating it is better to sharpen the blades on time and follow the right cutting conditions.
10. Replace the band saw blade immediatelly if any break off occurs.
11. After finishing cutting process do not leave the band saw blade tensioned on the machine, always loosen it.

Service

Tooth setting is done to 1/2 to 2/3 of the tooth height and is set by 1/2 to 1/3 over the size of band saw thickness. Tooth setting can be even bigger for soft woods but there must never happen that a piece of wood remains in between the teeth. Please keep the same distance while tooth setting the whole band saw blade. Pay special attention to regularity of setting (max. difference 0,1 mm). If not, nrun in of the blade might occur on the side where the bigger tooth set is.

Tooth sharpening is done by ceramic/CBN disc with medium grain roughness. Tooth face is sharpened. If the blade is extremely dull, it is possible to sharpen the tooth back as well. Prevent the tooth to become black from annealing (unwanted stage) while grinding. It is needed to keep the radius in the gullet, sharp edges in the gullet could cause blade breakage.

Recommendations How to Use Band Saw Blades

The most common causes of common troubles while cutting with band saw blades is wrong choice of band saw blade type, dimensions of blade or wrong tooth pitch for particular material. Not adhering to the correct cutting conditions is the second most common problem along with usage of insufficiently set or dull band saw blade.