Page:Sheet Metal Drafting.djvu/241

Rh The pattern is started by placing upon any straight line a distance equal to line 1–A of Fig. 322, this being a true length line since it rests on the horizontal plane. From point A point 2 is established and the pattern proceeds in the usual manner, using Fig. 325 for the spacing between the numbered points, and Fig. 323 for the spacing between the lettered points. The space between points 9 and 10 is taken from Fig. 324, and the line K–10 of the pattern is taken from line K–10 of Fig. 322 since it rests on the horizontal cutting plane and is, therefore, a true length.

The coal hod is generally made from two pieces of metal, locks being added parallel to lines A–1 and K–10 of pattern. However, if it is desired that the object be made from one piece, the development may be copied on the other side of line K–10 in Fig. 327.