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 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 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 this case, the letters indicate characteristics of the component:

• H = "Hardware"
• S = "Machine Screw"
• C0424 = "4-40, 3/4" long"
• PP = "Panhead Phillips"

• 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