Part Numbers
I have dealt with Part Numbers in a manufacturing environment, building projects for school and other, and trying to replace equipment that fails. I want to learn more about them to see if there is any standardization across industries.
Date Created:
References
Notes
A part number (often abbreviated PN, P/N, part no., or part #) is an identifier of a particular part design or material used in a particular industry. Its purpose is to simply reference that item.
- A part number should unambiguously identify a part design within a single corporation, and sometimes across several corporations.
- Example:
HSC0324PP
= "Hardware, screw, machine, 4-40, 3/4" long, pan head, Phillips". - A part number is n identifier of a part design, while a serial number is a unique identifier of a particular installation of that part design.
- A business using a part will often use a different part number than the various manufacturers of that part do. This is especially common for catalog hardware, because the same or similar part design might be made by multiple corporations.
- It's always a good idea to assign your own part numbers to products used in an assembly, even when the parts have a part number assigned by the manufacturer.
- In general, there are two types of part numbering systems: significant (
intelligent
) and non-significant (non-intelligent
). - In a significant part numbering system, the part numbers are assigned intelligently, according to an encoding system, and thus they give an indication of salient characteristics of the component.
- In non-significant part numbering system, part numbers are assigned in some other fashion, such as sequentially or arbitrarily.
- Significant part numbering systems can help identify an item from its code in a company (rather than a long description), but non-significant part numbers are easy to assign and manage.
- 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. - Another widespread tradition is using the drawing number as the root (or stem) of the part number; in this tradition, the various dash-number parts usually appear as views on the self-same drawing.
- Often more than one version of a part design will be specified on one drawing. This allows for easy updating of one drawing that covers a family of parts, and it keeps the specifications for similar parts on one drawing:
- It is a common concept in many corporations to add certain suffixes beyond, or in place of, the regular dash numbers, in order to designate a part that is mostly in conformance with the part design, but intentionally lacks certain features.
- Sometimes the terms
engineering part number
andmanufacturing part number
are used to differentiate thenormal
orbasic
part number (engineering PN) from the modification-suffixed part number. - For assemblies with reflection symmetry, which require parts that are identical except for being mirror images of each other, it is common practice to give them sequential dash numbers, or
-LH
and-RH
suffixes. - The term phantom part is sometimes used to describe a series of parts that collectively make up an assembly or subassembly.
- It is common today for part numbers to be marked on the part in ways that facilitate machine-readability, such as barcodes or QR codes.