Cap Screw Markings 1

[Laserxenon]

Could any one point me to an online refernce giving who manufactured a given cap screw by the letters marked on the fastener head (I have a screw that is marked only " T U Z ", and I cannot find who made it). Thanks, drew

 

[yates]

Try MIL-HDBK-57
Mil specs are available free on a website. I don't have details, but there have been other threads on on-line availability of MIL specs rtry FAQ or Search function.

 

[IFRs]

Not sure if it helps, but here is another site for fastener marking:

http://www.americanfastener.com/technical/grade_markings_steel.asp

 

[CoryPad]

This document, and other US defense/government documents, can be obtained at the ASSIST website:

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

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[deanc]

A "swag" on this would be a Grade 2 made in the pacfic rim.

Take a look at Google and search for "headmarks".

 

[Laserxenon]

deanc: i was under the impression that most or all of the black oxide cap screws were alloy steel with tensile strengths in the area of 150 ksi. Is that wrong?
Also, is there a reference that lists company specific headmarkings, ie.. TUZ= So and So company...??

 

[CoryPad]

Laserxenon,

Yes, there are publications that list company headmarkings. One of them was provided above by yates (MIL-HDBK-57) and is available at the URL I provided above.

Another is published by the Industrial Fasteners Institute and is available here:

http://www.industrial-fasteners.org/metric/index.html

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Paskenell]

NIST is responsible for registering all bolt head markings since the Fastener Law took effect. For a free pdf copy of their most current list, you may go to

http://www.uspto.gov/web/offices/tac/fqa/fqa.htm.

 

[deanc]

Paskenell has a good link-it is the US Patent Office. Been looking for something like this.

http://www.uspto.gov/web/offices/tac/fqa/fqa.htm

Most bolts can be ordered with a black oxide finish. If it has no markings other than the brand,I would consider it a Grade 2.

 

[boo1]

It appear to be, the markings are manufacture identifiers. Check, MIL-STD-1291A
Title: IDENTIFICATION SYMBOLS FOR AEROSPACE FASTENER MANUFACTURERS at:

http://assist.daps.dla.mil/docimages/0001/59/31/1291A.PD3