Below is an excerpt from “Mechanic’s Companion,” by Peter Nicholson.
- 45. Of Saws in general. Pl. 13. Fig. 6, 7, 8, 9, 13.
A saw is a thin plate of steel indented on the edge for cutting, by a reciprocal change in the direction of motion, pushing it from. and drawing it towards you. The cut which it makes, or the part taken away in a board, is a thin slice, contained between parallel planes, or a deep narrow groove of equal thickness. Saws are of several kinds, as the ripping saw, the half ripper, the hand saw, the panel saw, the tenon saw, the sash saw, the dove-tail saw, the compass saw, and the key-hole or turning saw. The teeth of these saws are all formed so as to contain an angle of sixty degrees, both external and internal angles, and incline more or less forward as the saw is made to cut transverse to, or in the direction of the fibres: they are also of different lengths and breadths, according to their use. The teeth of a saw are bent alternately to each side, that the plate may clear the wood.
- 46. The Ripping Saw
Is used in dividing or slitting wood in the direction of the fibres; the teeth are very large, there being eight in three inches, and the front of the teeth stand perpendicular to the line which ranges with the points: the length of the plate is about twenty eight inches.
- 47. The Half Ripper
Is also used in dividing wood in the direction of the fibres: the length of the plate of this is the same as the former, but there are only three teeth in the inch.
- 48. The Hand Saw, Pl, 13. Fig. 6.
Is both used for cutting the wood in a direction of the fibres and cross cutting: for this purpose the teeth are more reclined than the two former saws: there are fifteen teeth contained in four inches. The length of the plate is twenty six inches.
- 49. The Panel Saw
Is used for cutting very thin wood, either in a direction of, or transverse to the fibres. The length of the plate is the same as that of the hand saw, but there are only about six teeth in the inch. The plates of the hand saw and panel saw are thinner than the ripping saw.
- 50. The Tenon Saw, Pl. 13. Fig. 7.
Is generally used for cutting wood transverse to the fibres, as the shoulders of tenons. The plate of a tenon saw is from fourteen to nineteen inches in length, and the number of teeth in an inch from eight to ten. As this saw is not intended to cut through the wood its whole breadth, and as the plate would be too thin to make a straight kerf, or to keep it from buckling, there is a thick piece of iron fixed upon the other edge for this purpose, called the back.
The opening through the handle for the fingers of this and the foregoing saws is inclosed all round; and on this account is called a double handle.
- 51. The Sash Saw, Pl. 13. Fig. 8.
Is used by sash makers in forming the tenons of sashes: the plate is eleven inches in length. The inch contains about thirteen teeth; this saw is sometimes backed with iron, but more frequently with brass.
- 52. The Dove-tail Saw
Is used in dove-tailing drawers. The length of the plate is about nine inches, and the inch contains about fifteen teeth. This plate is also backed with brass. The handles of the two last saws are only single.
- 53. The Compass Saw, Pl. 13. Fig. 9.
Is for cutting the surfaces of wood into curved surfaces: for this purpose it is narrow, without a back, thicker on the cutting edge, as the teeth have no set. The plate is about an inch broad, next to the handle, and diminishes to about one quarter of an inch at the other extremity; here are about five teeth in the inch. The handle is single.
- 54. The Key-hole, or Turning Saw
Is similar to the compass saw in the plate, but the handle is long, and perforated from end to end, so that the plate may be inserted any distance within the handle. The lower part of the handle is provided with a pad, through which is inserted a screw, for the purpose of fastening the plate in the handle: this saw is used for turning out quick curves, as key-holes, and is therefore frequently culled a key-hole saw.