Figure 3-45. - Principles of template layout.

Figure 3-46. - Simple miter turn.

degrees desired. After you have the correct setting, and quarter lines. This establishes a base line for further layout work.

When you are measuring, treat the surface of the pipe as if it were a flat surface. Use a flat-steel rule or tape, which will lie against the surface without kinks, even though it is forced to follow the contour of the pipe. These angles can also be checked for accuracy by sighting with the square.

Use the protractor and square to determine the proper cutback for the desired angle of the miter turn. Start with the protractor scale set at zero so that the flat surface of the protractor and the blade are parallel. You can now set the protractor for the number of lock the blade. Place the protractor on the square with the bottom blade on the outside diameter of the pipe. Now read up to the cutback on the vertical blade of the square. You must be sure that the flat surface of the protractor is flush against the blade of the square (fig. 3-47). The outside radius of the pipe should have been determined during the quartering operation.

After you have obtained the cutback measurement, mark one half of this measurement off along the center line on top of the pipe. From the opposite side of the base line, measure off the same