Jointer (Drawing MTDC-1013)

When a crosscut saw is jointed, the teeth are filed to a uniform height. The jointer (figure 1) includes a crosscut file with its tang (the projection for attaching the handle) broken off. A worn file is better than a new file for use with the jointer. A new file might remove more metal than necessary.

Figure 1—The jointer allows a saw's teeth to be filed to a
uniform height before the cutting teeth are pointed (sharpened).
Long jointers, such as the one shown here, help maintain the arc of
the saw better than short jointers.

After the file is secured to the jointer, the jointer is run across the saw's cutting edge until all the teeth are cut down to the same height. When you see a flat or shiny spot on the tip of each tooth, you will know that the teeth have been cut to the same height. Some teeth will be cut down more than others. Longer teeth will be cut down the most. They may have a large flat spot. The shortest tooth will have only a glimmer of a flat or shiny spot.

Traditionally, filers used a short jointer, often combined with the raker gauge. We modeled our jointer after the "Gibbs" long jointer. The traditional peg- (tooth) and-raker saws used in the Forest Service were built with an arc-shaped design. The arc is important, because the arc determines how many teeth are cutting at a time. The MTDC long jointer has "two shoes" on either end that adjust to the shape of the saw, helping to maintain the saw's arc.