Band Saw Blade Break-In Procedures

note; sorry about the wording of these guidlines. the translation is a little hard to follow

All band saw blades, regardless of the manufacturer, need to be “broken in”. When new, the teeth are just too sharp. Cutting at full rate will cause fracturing of the feather edges, which will lead to premature blade failure.

Breaking in a band saw blade wears off this ultra sharp edge and allows the blade to retain its cutting ability longer. Each manufacturer has their own preferred method for blade break-in. However, they all share the same principles:

                           1. Maintain recommended band speed
                           2. Reduce feed pressure to 1/2 normal rate
                           3. Run at these settings for the first 50 square
                               inches of material cut (150 square inches on
                               mild and low carbon steel)

Note: If you are unsure what the normal feed pressure is, start light. Increase feed pressure until good curly chips start to form. After cutting the recommended area, slowly increase the feed pressure until you reach your desired cutting rate. Special consideration must be given while breaking in a saw blade on nickel-based alloys (stainless steel, inconel, hastelloy, D2 tool steel, etc.). These alloys tend to harden very quickly; therefore, sufficient feed pressure must be applied during the break-in period to remove some material. As a general rule, alloys sawed at
lower speeds need more pressure during break-in. Refer to this checklist if you have any problems with your band saw blade’s operation.

Band Saw Blade Troubleshooting

Stripping Teeth

• Too many teeth or too few teeth in the cut
  
• Parts are not held securely
  
• Feed rate too high or speed too slow
  
• Chip brush not working, causing chips  to overload gullets
  
• Check coolant concentration

Band Breakage

• Worn guides
  
• Guide arms set too far apart
  
• Diameter of wheels too small, use thinner bands
  
• Band tension too high
  
• Poor butt weld

Crooked Cut

• Dull blade
  
• Improper blade break in
  
• Guide arms too far apart or out of alignment
  
• Damaged roller or carbide guides
  
• Feed rate too heavy or blade speed to slow
  
• Vise clamp out of square.

• Improper blade break in
  
• Check coolant concentration and flow
  
• Check chip brush
  
• Check feed rates and blade speed
  
• Improper tooth pitch

Rough Cut

• Band speed too slow and feed rate too high
  
• Improper blade break in
  
• Dull or damaged teeth
  
• Check chip brush
  

How to Choose the Correct Band Saw Blade Number of Teeth Per Inch

The number of teeth per inch (TPI) is important in obtaining the finish desired and the proper feed rate. A coarse tooth blade (2, 3 TPI) should be used for resawing wood and cutting thicker stock up to 8". A fine toothed blade (18 to 32 TPI) should be used for thinner metals and plastics under 1/4". For general cutting of 3/4" wood 4 TPI will provide a fast cut and 14 TPI will cut slow but leave a smoother finish.

When Selecting TPI remember:

More TPI give a smoother but slower cut

Fewer TPI allow a faster cut with a slightly rougher finish

At least three teeth must be in the workpiece - the chart below will help you decide.

   To determine the SFM

    It is important to know the SFM for the various speed settings of your band saw, so that you can select the proper speed for cutting wood or other materials. Check the operator's manual of your band saw to determine the SFM or use the following procedure:

1. Determine the RPM: check the operator's manual or clock the revolutions per minute of the wheels with a tachometer or revolution counter.

2. Measure the diameter of the drive wheel in inches and multiply by .262 to obtain the wheel circumference. The RPM times circumference equals the surface speed of the blade. RPM x diameter in inches x .262 = SFM.

How to Choose the Correct Band Saw Blade Width

Band Saw Blade WidthBlade width is measured from the tips of the teeth to the back edge of the blade as shown above. The instructions for the particular machine being used should be followed when selecting blade width.

If no such instructions are provided, blade width should be determined with the following guidelines:

• For Cut-Off Sawing , the blade should be as wide as the machine will allow. The wider the band is, the straighter the cut will be. Faster feeding can be achieved.

• For Contour Sawing , the blade should be as wide as the machine allows, but still narrow enough so that it can cut the desired shape (radius),

Band Saw Blade Tooth Shape Styles

Regular Band Saw Tooth Style The most commonly used tooth shape. Ideally suited for both cut-off and contour sawing of most materials. For cutting thin materials where a fine cut is required.

Skip Tooth Band Saw Blade StyleWidely spaced teeth with a 0° rake angle to prevent clogging when cutting soft, non-ferrous metals, plastics and wood.

Hook Style Band Saw Blade StylePositive 10° rake angle helps to "digin", resulting in a higher cutting rate. Recommended for long cuts into thicker wood, plastic and metal.
Band Saw Blade Tooth Set

Raker Band Saw Blade SetThe raker tooth set consists of one to the left, one to the right and one tooth (raker) is unset. This set is used for cutting thick, solid metal sections on horizontal cut-off machines. It is also used for contour cutting and resawing on vertical band machines.
Alternate Band Saw Blade Tooth SetAlternate set or double alternate plus raker set blades are designed for cutting wood. Provides faster, smoother cuts.
Wavy Band Saw Blade SetThis set pattern has groups of teeth set to the left and to the right, separated by unset raker teeth. It is made primarily with small teeth and is recommended for cutting thinner sections - tubes, pipes, thin sheets and other small shapes. 32 TPI only.