Читать книгу The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking - Paul N. Hasluck - Страница 11

A straight-edge 15 ft. long, 6 in. wide, and 1 1/4 in thick is large enough for all practical purposes of the joiner, mason, bricklayer, engineer, millwright, etc. The best material is pine, it being the least affected (permanently) by change of temperature or weather. The pine board must be cut from a straight-grown tree, as a board from a crooked trunk will not keep parallel and straight for any length of time, owing to the grain crossing and recrossing its (thickness) edge. Straight-edges are made from all parts of boards cut from whole logs, but they cannot be relied upon to keep perfectly straight and true for any length of time. A strip that has been made without regard to the position it had in the whole tree will have to be trued up occasionally, and it therefore can never be relied upon unless tested each time it is required to be used, which is a great annoyance.

Fig. 2.—Striking Knife and Marking Awl.