Marking & Certification bolting materials L7 - ASTM A320

[federella]

We have ordered boltings in L7 ASTM A320 but with an impact test at minus 20°C instead of standard minus 101°C because minus 20°C is our intended service temperature.
We do not know:
1. what would be the stamping of the pieces?
2. what must be written on the materail certificate as to distinguish fro the standar L7 impact test at minus 101°C?
3. Where is clearly indicated on the ASTM standards how mast be marke and certified?
I read ASTM A320, A370 and A962 without find clearly indications.
On ASTM A320 para. 6.2.1.1 is generically indicated " ..... and the bolting is suitably marked to identify the reported test temperature""

Thanks for you help
V.Federella

 

[metengr]

I have reviewed ASME SA-320 and offer the following;

1. For all studs equal to and greater than 3/8" in diameter the grade and symbol of the manufacturer shall be marked on one end of the stud. For all bolts 1/4" and greater in diameter, the grade and manufacturer symbol shall be marked on the head. For threaded bars that are bundled, the item must be tagged or the box marked with the grade and manufacturer name or symbol.

2. The impact test is a minimum requirement. Per this specification, the L7 stud or bolt material shall have a minimum of 20 ft-lbs at -101 deg C. Any service temperature above this temperature complies with the impact test requirement.

3. You need to review ASME SA-320 specifically Section 3). Ordering Information for the PO and 14). Product Marking

 

[QAFitz]

federella,
Paragraph 6.2.1.1 of the ASTM Standard A320(05a) indicates "...and the bolting is suitably marked to identify the reported test temperature."
From a purely black & white view this can only mean that the head of the bolt is marked (stamped) with -20. That way whoever uses the product knows to look for an explanation of the -20.
Other than that it may get a little gray. Paragraph 11.2 (Product Marking) indicates that "...bolting material including threaded rod may be bundled and tagged...". Who classifies this as bolting material and therefore allowed the bolts to be tagged is the question. If that person gives it to you in writing then "bundled and tagged" may be acceptable for this application (only). The risk is if they ever get used for another application: the product is not physically marked so the question may not be raised (researched).