This section is from the book "Spons' Mechanics' Own Book: A Manual For Handicraftsmen And Amateurs", by Edward Spon. Also available from Amazon: Spons' Mechanics' Own Book.
The following valuable suggestions on the purchasing of saws are given by Disston, the well-known saw-maker of Philadelphia. The first point to be observed in the selection of a hand-saw is to see that it " hangs " right. Grasp it by the handle and hold it in position for working. Then try if the handle fits the hand properly.
These are points of great importance. A handle ought to be symmetrical, and as handsome as a beautiful picture. Many handles are made out of green wood; they soon shrink and become loose, the screws standing above the wood. An unseasoned handle-is liable to warp and throw the saw out of truth. The next thing in order is to try the blade by springing it. Then see that it bends regular and even from point to butt in proportion as the width of the saw varies. If the blade be too heavy in comparison to the teeth the saw will never give satisfaction, because it will require twice the labour to use it. The thinner you can get a stiff saw the better. It makes less kerf, and takes less muscle to drive it. A narrow true saw is better than a wide true saw; there is less danger of dragging or creating friction. You will get a smaller portion of saw-blade, but you will save 100 dollars' worth of muscle and manual labour before the saw is worn out. Always try a saw before you buy it. See that it is well set and sharpened, and has a good crowning breast; place it at a distance from you, and get a proper light to strike on it, and you can see if there be any imperfections in grinding or hammering. We set our saws on a stake or small anvil with one blow of a hammer.
This is a severe test, and no tooth ought to break afterwards in setting, nor will it, if the mechanic adopts the proper method. The saw that is easily filed and set is easily made dull. We have frequent complaints about hard saws, but they are not as hard as we would make them if we dared; but we shall never be able to introduce a harder saw until the mechanic is educated to a more correct method of setting his saw. The principal point is that he tries to get part of the set out of the body of the plate when the whole of the set must be got out of the tooth. As soon as he gets below the root of the tooth to get his set, he distorts and strains the saw-plate. This will cause a full-tempered cast-steel blade to crack, and the saw will eventually break at this spot.
Grimshaw says that a hand-saw must be springy and elastic, with almost a "Toledo blade" temper. There is no economy in buying a soft saw; it costs more in a year for files and filing than a hard one does, dulls sooner, drives harder, and does not last so long. A good hand-saw should spring regularly in proportion to its width and gauge; that is, the point should spring more than the heel, and hence the curve should not be a perfect are of a circle. If the blade is too thick for the size of the teeth, the saw will work stiffly. If the blade is not well, evenly, and smoothly ground, it will drive hard and tend to spring. The thinner the gauge and narrower the blade, the more need for perfectly uniform and smooth grinding; the smoother and more uniform the grinding, the thinner and narrower a saw you can use. The cutting edge is very often made on a convex curve, or with a "crown" or "breast," to adapt it to the natural rocking motion of the hand and arm. By holding the blade in a good light, and tapping it, you can see if there are imperfections in grinding or hammering. Before buying a saw, test it on about the same grade of work as it is intended to be put to. It is a mistake to suppose that a saw which is easily set and filed is the best for use. Quite the reverse is the case.
A saw that will take a few more minutes and a little harder work to sharpen will keep its edge and set longer than one which can be put in order quickly, and it will work better in knots and hard wood.