A part number is a unique identifier of a part used in a particular industry. Its purpose is to simplify referencing to that part. A part number unambiguously defines a part within a single manufacturer.

For example, when specifying a screw, it is easier to refer to "HSC0424PP" than saying "Hardware, screw, machine, 4-40, 3/4" long, panhead, Phillips".

User Part Numbers vs. Manufacturer Part Numbers (MPN)

A business using a part will often use a different part number than the various manufacturers of that part do.

For example, when referring to a "Hardware, screw, machine, 4-40, 3/4" long, panhead, 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 manufacturer, because they are identical. 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 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.

Significant vs. non-significant part numbers

In general, there are two types of part numbering systems: significant (a.k.a.: Intelligent) and non-significant (a.k.a.: non-Intelligent).

• In a Significant Part Numbering System, the part numbers are assigned intelligently and are an indication of salient characteristics of the component. For example, a screw may have the part number "HSC0424PP".
• In a Non-Significant Part Numbering System, part numbers are assigned in some other fashion, such as sequentially. For example, a screw may have the part number "1002".

Significant part numbering systems are easier to use, though a new part number is harder to assign.

See also

• GTIN
• Stock Keeping Unit

References

• partnumber.com Significant Part Number assignment utility
• Design Chain Associates and BPIC Arguing against intelligent part numbering systems
• Seradex Discusses part numbering systems

External Links

• Part Number Database