Читать книгу The Handyman's Book of Tools, Materials, and Processes Employed in Woodworking - Paul N. Hasluck - Страница 19

A crenelated square has a tongue in which there is a series of crenelations or notches at the graduations. It is especially useful in marking off mortises, etc., though it is available for all other ordinary applications. Three sides of a piece of timber can be set out without moving the work. To use this square, say in marking out a mortise or tenon, take it in the left hand and lay its tongue upon the surface of the work, as in Fig. 20. The lower end of the main arm is lowered for 2 in. or so from the surface to get a better purchase, and then an awl, held in the right hand, is placed in a notch at the correct distance from the edge to mark the left-hand edge of the mortise or left-hand face of tenon as the case may be. Then push the square forward, pressing it down gently upon the work, and one mark will have been made. Replace the square, and with the awl in another notch at the thickness of the tenon or width of the mortise make a second mark. Horizontals are drawn by means of the smooth edge of the tongue (see Fig. 20).

Fig. 16.—Adjustable Try Square.

Fig. 17.—Ordinary Sliding Bevel.

Fig. 18.—Brass Frame Sliding Bevel.