Tool Tips

Boston Saw & Tool – Tool Tips

Info to Help You Improve Performance and Extend the Life Of Your Valuable Solid Carbide and Carbide Tipped Router Bits!



Solid Carbide: Primarily used in CNC operations. Material provides best rigidity and long tool life.

Carbide Tipped: Incorporates the wear resistance of carbide and the toughness of a HSS body-mainly hand held.

HSS: Primarily used in hand routing. Material provides a tough body and sharper cutting edge. Good in CNC.


Straight flute: Offers a neutral cutting action - highest force

Upcut flute: Provides the best surface finish and allows for good chip extraction. May cause part lifting if vacuum or fixturing is not sufficient.

Downcut flute: Provides a downward force which helps eliminate part lifting. Chip rewelding MAY occur if there is no space below the part for chip expansion.

Compression: Used for laminated materials, produces a good top and bottom finish on the part.


Single Flute: Allows for larger chiploads in softer materials

Double Flute: Allows for better part finish in harder materials.

Multiple Flutes: Allows for an even better part finish in harder materials.

NOTE: As the number of cutting edges increase, your feed rate should increase to prevent burning and premature tool dulling.


  1. Start off using the recommended chipload and RPM for the material you are cutting.

  2. Increase the feedrate until the part finish starts to decrease or you risk moving the part off the vacuum. Decrease the feed by 10%.

  3. Next, decrease your RPM by a set increment until your surface finish deteriorates again. Once this happens increase your RPM until the finish is acceptable.

  4. You have now optimized your speed and feed by taking the largest chip possible.

Note: This should be done in the first sheet of material to prevent tool dulling due to excessive heat.


If a feed rate is too low heat will be generated causing the cutting edge to break down and dull quickly. To check this, run a nest of parts and stop the spindle. When the spindle has stopped rotating, carefully feel the tool’s temperature. It should be at or near room temperature.

If the tool is hot review “Optimizing Speed and Feeds”.


If a condition arises where multiple tools should break follow these steps to solve your problem:

  1. Are you using the proper tool for the job?

  2. Make sure your collets and tool holders are clean and the tool is colleted properly.

  3. Check your speed and feed (is your tool hot?)

  4. Is your depth of cut too excessive for the material you’re cutting?

  5. Do you have any part movement?

  6. Do you have ample part hold down?

  7. Stop running parts and check with your distributor or Onsrud’s Technical Support.

If you have to contact Boston Saw & Tool for technical support, have the following information:

  1. Machine being used.

  2. Material being cut.

  3. Part number of tool along with the batch number which is below the part number.

  4. Speed / Feed / Depth of cut.

  5. Where did the tool break (flute, shank, or in the collet)?

  6. How long did the tool work before it broke?

  7. Have you done this operation in the past using this tool?



Collets have a life span of 3 months if used 8 hours a day. Replacing the collets will ensure your operation runs consistently and prevents tool breakage. When inserting a tool into the collet make sure the flute fadeout does not enter the collet. This will cause run out and potentially lead to tool breakage. To ensure proper clamping the tool shank should fill, at the minimum, 80% of the depth of the collet. If this cannot be achieved, use a collet life plug to ensure a proper clamping effect.


Cleaning is an essential part of collet maintenance. As material is cut it causes the collet, tool holder, collet nut and spindle to become dirty. This causes your tool to cut in an elliptical fashion which will decrease tool life and cause inconsistency in your operation. Collets, tool holder, and collet nut should be cleaned daily using the Rust Free solvent and a brass brush. Refer to the critical areas diagram to see which surfaces must be clean.



  1. Spray the cleaner on the surface and allow it to soak for a minute

  2. Use a brass brush to clean the surface thoroughly.

  3. Rinse off using distilled alcohol. Feel the surface using your fingers to make sure the surface is clean

  4. Apply a small amount of lubricant to prevent rusting.

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