Creative Woodworks & crafts 2004-11, страница 40

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Saw P)lade Development

by Ralph Costa |

From Cro-Magnon to 17th-Century England

Recorded history concerning saw blades is scarce, but in my travels I've managed to gather enough information to create this brief outline. Being in the saw blade industry, I thought it would be interesting to see how far into the past one could go.

Let's go back about 60,000 years. Yes, believe it or not, indications are that Cro-Magnons had actually developed a cutting instrument with teeth. They were only flint knives, but they did have a toothed edge. The teeth were obviously not uniform, but nonetheless, they illustrate that humans formed serrations on edges of hard materials that functioned as cutting tools.

From Cro-Magnon we jump straight to the Egyptians. In this period, about 6000 years ago copper is discovered. The Egyptians soon made goocl use of the newly found metal and began creating small hand saws. They were about 18" long with a wooden handle lashed to one end of the blade. What an advancement! Hence, the handsaw is born, and the evolution begins.

Four thousand years pass and the Egyptians discover- another new metal-bronze. Bronze proves to be more durable than copper, so the saw undergoes a revision. Blade life increases with this new metal, but there remains a major problem: when making deep cuts, the blade would bind in the work. So, to keep the blade moving freely, oil and wedges were used. This method of keeping the blade from binding was standard for a long period of time, but improvements were still needed.

The next set of improvements was made by the Romans between 100 B.C. and 300 A.J). They found that by slightly bending the teeth in opposite directions, the back of the blade did not bind in the work and the blade oscillated freely without oil and wedges. Also, the waste was conveniently expelled.

After putting on the blade teeth what we now know as "set," the Romans developed a saw frame. Hie frame held the blade at both ends. This feature kept the blade straight while cutting and

made it possible to design a much narrower blade. The Romans also enhanced tooth design with more of a "V" shape, giving the blade a better cutting edge.

One could say, then, that the modern saw was created by the Romans, and that they inaugurated tooth set and kerf.

The next improvement comes around the middle of the 17th century in Sheffield, England. This region of England, by far, contributed reams of data relating to steel processing. The one process in particular that aided saw blade development was rolling steel into plates. These plate allowed flat, wider hand saws, which resembled the saws we have today, to be fabricated.

Fret and Scroll Saw Blades

What about fret and scroll saw blades? Ah, this is where it gets interesting.

As mentioned in the beginning of the article, not much has been recorded regarding saw blades. But fret saw manufacturers were fanatical about keeping information about the blades secretive; anything useful was closely guarded right from its inception. However, I did finally manage to gather some facts.

The farthest back that 1 was able to confirm the existence of fret saws is about the 1800s. 1 found a 1928 German publication named Dmht-Welt (or Wire-World), which directly referenced fret saw blades from this time.

Let's start with the name. In German, the name for a fret saw blade is laub-sage (pronounced loub-say-ga). Believe it or not, laub literally means "leaf" or "leaves," and sage means "saw."

Now, what do leaves have to do with fret saws? It was believed by-some that the tooth of the fret saw blade resembles the edge of a tree leaf. There is no reference to a particular tree, but the name stuck. The earliest blades were supposedly conceived when an inventive person needed a small saw blade to do some decorative cutting. Word has it that a main spring from a clock was straightened out and the teeth formed to the edge. Some say the teeth were filed and some say they were punched. Regardless of the method, a new product and a new industry was soon to be bom.