Page:Sheet Metal Drafting.djvu/27

Rh measuring lines of the stretchout. Extension lines carried over from the elevation locate the top and bottom lines of the pattern. The side lines of the pattern are formed by measuring lines No. 1 and No. 6. Small free-hand circles should be placed as shown to indicate to the workman where the bends are to be made. The views and the pattern must be fully dimensioned.

10. Related Mathematics on Sheet Metal Cleat.—If the drawing is correct, the sum of all the lines in the profile will be equal to the length of the line of stretchout.

Problem 1A.—Compute the sum of all the lines in the profile from the dimensions given in Fig. 17. Measure the length of the line of stretchout in Fig. 20 and compare with the sum of the profile lines. If the answers do not agree, either the drawing or the arithmetic is incorrect. They should be made to agree.