Blog 

A friend recently called me to take a look at a blueprint of a standard part (a cap), and to compare it to pictures he had taken of the actual part. It was obvious to both he and I that the part had been misidentified as to its part number; the part actually visually conformed to another part number. The part had been in the aftermarket for some time, so the OEM paperwork to identify who fabricated the offending part could not be located, and thus notified. There remained two options however. The first is to locate the manufacturer's identification code, symbol, or brand logo.

These actually exist on many parts, and are typically used on small parts where the entire manufacturer's name cannot fit on the part. It may be a logo, symbol, code, or simply the manufacturer's initials. In the case of this cap, it was a symbol, and in fact reminded me of the branding symbols you might find on cattle in the wild west. As you may expect, the symbol did not give us a clue as to who among thousands of manufacturers it may apply to.

Fortunately, there is a government publication that has done an outstanding job of compiling such symbols, and attributing it to the applicable manufacturer. It is MIL-HDBK-57C(IS), titled "LISTING OF FASTENER MANUFACTURER'S IDENTIFICATION SYMBOLS". It is a Department of Defense publication. Below is an excerpt.

Note the symbol, followed by the manufacturer's name, and the page where more information about the manufacturer can be found. Also, despite the title of this publication, I assure you that these same symbols exist on other commodities besides fasteners.

Free copies of this publication can be downloaded at the following address:

http://assist.daps.dla.mil/quicksearch/

On the document ID line, type in MIL-HDBK-57.

You may use this publication very rarely, but it helps to establish trace when in question. Besides, when you produce it, your colleagues will be very impressed.

The second method of identifying the manufacturer is to locate the part's CAGE code, if provided. A free web site to search such codes is:

https://www.bpn.gov/bincs/begin_search.asp

I like free stuff don't you?

ROYBOY'S TIPS: Don't confuse all those inspection stamps with the actual manufacturer symbol. After a part has passed inspection, it is common for the inspector to stamp the part, and in fact you may find several such inspection stamps on the same part.

7/26/07

Roy Resto - VP Technical Operations, FAA-DAR
Phone: 414 875-2191   Fax: 414 875-0200
royboy@mbtrepair.com

site map