Wallis, Rolland S. [from old catalog], Iowa state college of agriculture and mechanic arts, Ames. Dept. of engineering extension. [from old catalog] · Ames, Iowa, Engineering extension department, Iowa state college · leaf 7
nable with steel blades and cast-metal heads. Wood blades with transparent celluloidedges (Fig. 3d) are popular. There are two working edges (Fig. 3b)—the sliding edge on the headand the drawing edge on the blade. While the lower and upper edgesof the blade are usually parallel, the lower edge… … Blade (b) Celluloid Reinforcing Strip af End of Blades r (d) Celluloid Edges (ei • 1 u (f) Fig. 3.—T-squares. Either an extra swivel head (Fig. 3a) or an adjustable blade (Fig.3c) are convenient in work involving many parallel lines at odd angles.The micrometer screw in the head of the latter style…
Mechanical drawing
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