Unit 4 Title Blocks and Notes 51 Copyright Goodheart-Willcox Co., Inc. Scale Block The scale block indicates the scale of a drawing. Refer to Figure 4-4(G). Typically, a drawing has one scale as noted in the scale block. However, drawings with different scales may be required to specify a part or assembly. VARIES in the scale block indicates multiple scales are on a sheet. Each drawing will have a separate scale noted. When a drawing has no specifi c scale, DRAWING NOT TO SCALE may be on the drawing sheet and NTS (not to scale) in the scale block. Goodheart-Willcox Publisher Companies use coding systems similar to these for establishing drawing numbers. Drawing numbers are for drawing identification, as well as for archiving purposes. Figure 4-5 Drawing number series Sheet size Organization designation Drawing revision character Original project number issued in the given year Year the project was issued Main organization number Drawing type prefix Secondary branch, division, or department number Goodheart-Willcox Publisher The drawing number and related information can be located in the margin above the revision block at the upper-right corner of a drawing sheet. Figure 4-6 Drawing number Sheet number Revision character When working on a project, it is important to check the drawing number and revision letter before proceeding with any specific work operations. Prints with similar drawing numbers can easily be mistaken for another. Checking the revision letter prevents you from making a part with old specifications. Double-checking the drawing numbers and revision letters will prevent costly mistakes. PRO TIP