Inventory Files of Spider Gauges Used With Saws

Spider gauges

For use with saws there are some special gauges.

1. For use with the cutter teeth there are the "spider gauges". A spider gauge is used to help with giving a saw the correct "set". Set is the distance from the center line of a saw that the tooth is bent out. Thus a saw with teeth that extend from the center line by .012 inch, (in many applications a set of .012 is common) have a set of .012.

   It is essential that all teeth on a saw have the same set. If some teeth have greater sets than other, the saw will be more difficult to move when pulling it through the kerf. However if the set is too small then the kerf will bind against the saw causing difficulty in pulling the saw. The set is one of the most important characteristics of a saw in ensuring that it cuts quickly and easily.

   Depending on the type and condition of the wood the set may be changed. I.e. an old dry log will require less set than a fresh log with much pitch in it.

2. Rakers, or cleaner, teeth do not have a set to them. For raker teeth they must all be at the same height relative to the cutter teeth. Otherwise they will impede the actions of the cutter teeth.

3. The various spider gauges that I have have a range of .000 inch to .038 inch. An additional one is a variable distance spider gauge with a wide range.

   The "standard" spider gauge has two ends with a fulcrum part way on the gauge. This gives two "depths" (actually distances from the saw center line) that the spider gauge is useful for.

   Spider gauges are fixed as to the "depth" that they set to work with. I have looked is several period publications (Atkins, Disston and Simmonds) to try and determine if their spider gauges were supplied with any preferred amount of "depth". There was no mention of a preferred "depth". I assume that each saw filler adjusted the "depth" of his spider gauge by careful grinding one end or the other so that his saws would be correct for the work that they would be doing. Note that when sawing a piece of wood, or end of a spider gauge, that you can not make it longer!

4. Jim Thode has a web site with an interesting discussion of making a spider gauge replacement that will work with narrow saws. Unfortunately he has placed a useful link near the bottom of the page that gets to his saw stuff which may not be obvious.

In the following spider gauge data there are two numbers given: (all distances are in inches)

1. Short This is distance that the shorter end of the gauge is "up" from the saw center line when the other end is placed directly on the saw.
2. Long This is distance that the longer end of the gauge is "up" from the saw center line when the other end is placed directly on the saw.

Anderson and Disston Spider Gauges

Simonds Spider Gauges