Popular Woodworking 2006-10 № 157, страница 20

Arts & Mysteries

I think set is especially helpful for work in soft, sappy woods such as pine. Waxing or oiling your saw blade also helps.

There is no magic to handsaws. Remember that pitch is chiefly governed by stock thickness but it can also affect accuracy at the start of a cut. Adding rake makes the cutting smoother but slower. Fleam is added for cross-grain work, and set helps reduce friction. Blade thickness primarily affects the speed of the cut, and the length of a blade for rough cuts should be chosen according to your stroke. For finer work, shorter saws are generally better. Armed with all this in mind, you should be able to look at any saw and know what it would be good for by examining its teeth. Conversely, you now should be able to p ick the right saw for the job. Rather than replace a manufacturer's lame tooth recommendations with my lame recommendations, my goal for this article was to raise your awareness that:

a) There is no standard way to shape a saw tooth for all cutting situations you will face.

b) You can shape saw teeth to achieve different effects (ease of starting, speed, good for softer or harder woods, etc.).

c) Choose the tooth shapes (or the saw) based on your work - not hearsay, my recommendations, or other subjective reviews. PW

The teeth on this rip saw are moderately set. This blade is .040" thick here. The amount of set appears to be a quarter of that. The amount of set on a lightly set saw is barely perceptible. It may be only a few thousandths (V1000) of an inch on either side. But what may not be obvious to the eye can easily be felt during sawing. Notice how crisp the outer corners of the teeth are. I avoid stoning the sides of my saws' teeth (a common way to reduce a saw's set).

CHOOSING A "SAWPLATE"

When choosing teeth for a saw, two other factors greatly influence the performance: the length and thickness of the blade (sometimes called the "sawplate").

Blade Thickness

For rough work in thick wood, large teeth are best (small teeth clog in thick stock). Because large teeth require more force to push, a thick blade is better because it will resist buckling. When you have a choice, marry coarse teeth to a thick blade.

For thin, hard wood, you need fine teeth, possibly with a positive rake. This will be a slow-cutting saw if the blade is thick. Choosing a thin-bladed saw for these teeth will improve your speed.

Blade Length

Your ripsaw's blade should be as long as your arm. (You can measure from your armpit to the end of your fist.) Long saws cut fast. But a 24"-long dovetail saw would be nearly

impossible to use. Common sense tells us we need shorter saws for precision cuts and cuts in thin material. And that's pretty much what we see manufacturers producing : short saws with fine teeth for thin stock, long saws with coarse teeth for thick stock.

The exception is the 18th-century tenon saw. It was used to saw the wide tenon cheeks on everything from doors to frame-and-panel furniture. These saws typically have fine teeth and thin blades for precision cuts, but are very long, typically 16"-20". Their length compensates for their fine pitches, allowing quick work through thick stock. Though largely unavailable for the past century, some custom sawmakers are now building them again.

So just as we married fine teeth to thin saw blades, we should marry fine teeth (for accurate cuts in thin stock) to shorter blades, with the exception being the traditional tenon saw. — AC

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Popular Woodworking October 2006