Editing Part number (section)

==Dash numbers==
There is a strong tradition in part numbering practice, in use across many corporations, to use suffixes consisting of a "dash" followed by a number comprising 1 or 2 digits (occasionally more). These suffixes are called '''dash numbers''', and they are a common way of logically associating  a set of detail parts or subassemblies that belong to a common assembly or part family. For example, the part numbers 12345-1, 12345-2, and 12345-3 are three different dash numbers of the same part family.

In precise [[typography|typographical]] and [[character encoding]] terms, it is actually a [[hyphen]], not a [[dash]], that is usually used; but the word "dash" is firmly established in the spoken and written usage of the engineering and manufacturing professions; "dash number", not "hyphen number", is the standard term. This comes from the era before computers, when most typographical laypeople did not need to differentiate the [[character (symbol)|characters]] or [[glyph]]s precisely.

Some companies follow a convention of circling the dash numbers on a drawing, such as in view designators and subpart callouts.