Editing Part number (section)

==User part numbers versus manufacturing part numbers (MPN)==
{{anchor|MPN}}A [[business]] using a part will often use a different part number than the various [[manufacturing|manufacturers]] of that part do. This is especially common for catalog hardware, because the same or similar part design (say, a screw with a certain standard thread, of a certain length) might be made by many corporations (as opposed to unique part designs, made by only one or a few).

For example, when referring to a "Hardware, screw, machine, 4-40, 3/4" long, Phillips":
*Manufacturer A uses part number "4-40-3/4"-pan-phil",
*Manufacturer B uses part number "100-440-0.750-3434-A".
*Manufacturer C uses part number "TSR-1002".
The business using such a screw may buy screws from any of those manufacturers, because each supplier manufactures the parts to the same specification. To identify such screws, the user doesn't want to use any of those manufacturer's part numbers, because
* it would imply that one manufacturer is acceptable and the other ones aren't, and,
* it wishes to use a consistent [[:wikt:format|format]] for the part numbers of all of the parts it uses.
Therefore, the user devises its own part numbering system.
In such a system, the user may use the part number "HSC0424PP" for that screw.

There are also some national and industry-association initiatives which help producers and consumers codify the product based on a unified scheme to establish a common language between industrial and commercial sectors. For example: 
* The Iranian national classification and codification system known as [[Irancode]] is a 16 digit code to codify the products in a nationally unified manner.
* The U.S. government, and most especially its Department of Defense, has standardized various part numbering systems over the decades for it and its suppliers to use, such as the AN (Army-Navy) and MS (Military Standard) hardware classification and numbering systems.
* The [[Aerospace Industries Association]] maintains the NAS system (National Aerospace Standards), which is gradually replacing the AN and MS systems.
* The [[ASME]] provides a codification of fastener specifications in B18.24 Part Identifying Number (PIN) Code System Standard for B18 Fastener Products.