Tool, the word, comes probably from toil, signifying the thing with which one toils or labors, a hammer, file or wrench; a tool never ceases to be a tool, i.e., something which is applied directly to the work; generally tools in machine practice cut, abrade, like a file, or strike—as a hammer; a tool is that which is brought to bear directly on the work; again, it is any implement used by a craftsman at his work; it is any instrument employed for performing, or aiding to perform, mechanical operations by means of striking, penetration, separation, abrasion, friction, etc.
Again in practical mechanics the word tool has a restrictive meaning; a single device, as a chisel, crowbar or saw, or a very simple combination of moving parts, as tongs, shears, pincers, etc. These latter for manual use, are always called tools, although embodied in the strict technical definition of machine.
Such machines as are used in shaping materials in the construction of the parts of other machines, and also many of those which perform work, such as boring, planing, riveting, etc., formerly only done by hand, and still performed manually to a greater or less extent, are nearly always called machine tools; the term, engine tool, is more in accord with general usage when referring to large and complicated machines.
It is by his knowledge of the application of hand-tools and their practical use, that the pump attendant is judged by those around him. The skillful mechanic, who with many others, constructs a machine, may be neglected, but one who skillfully operates the apparatus, seldom fails of due credit and reward, hence these paragraphs are intended to emphasize the importance of these more humble implements.
Fig. [610] represents a pipe cutter—a hand tool specially used for cutting of wrought iron, steel or brass pipe. This tool consists of a cast steel body, tapped in one end to receive the adjusting screw or handle which also serves to rotate the tool when applied to a pipe. The cutting is generally effected by a hardened cast steel cutter with cutting edges having angles of about 60° like a V thread; an enlarged form of this cutter is shown in the engraving.
Fig. 611.
Fig. [611] shows a ratchet drill; this is a tool in which the rotary motion of the drill is derived from a ratchet and pawl actuated by a lever or handle. There are various forms of this class of tools. This one is the “Packer ratchet.” The thread for adjusting or feeding the drill is protected from chips and dirt by a sleeve which covers the shank.
The center is of tempered tool steel as well as the ratchet and pawl. The socket is usually made square.