SA 194 nu marking

[vanmorrison]

It is debatable if I should post this in this forum or in the Welding, Bonding & Fastener forum...Dear ASME (mechanical) Code Forum :

Recent editions of SA 194 specifies that Manufacturer & grade markings are to be stamped on the nut face. It then states marking on the wrench flats ... is prohibited unless approved by the purchaser.
Does this mean; 1. no markings whatsoever on the wrench face or 2. Is it the intent that markings must be on the face and additional markings on the wrench flats is of no consequence?

Nuts were received that have been marked with the manufacturer & grade on both the face and wrench flats. I have never seen this before.

The purchase order specified Code Effective Date 1974. To my knowledge this Edition of SA 194 does not specify the placement of markings. If this is correct does this mean markings can be placed anywhere on the nut and more recent Code Edition marking placement requirements are not applicable?

I look forward to your comments.

 

[metengr]

A 194-00

12.2 Nuts shall be legibly marked on one face to indicate the grade and process of the manufacturer, as presented in Table 7.Marking of wrench flats or bearing surfaces is not permitted
unless agreed upon between manufacturer and purchaser. Nuts
coated with zinc shall have an asterisk (*) marked after the
grade symbol. Nuts coated with cadmium shall have a plus sign
(+) marked after the grade symbol.
12.3 For purposes of identification marking, the manufacturer
is considered the organization that certifies the fastener
was manufactured, sampled, tested, and inspected in accordance
with the specification and the results have been determined
to meet the requirements of this specification.

Your phrase...

Marking of wrench flats or bearing surfaces is not permitted
unless agreed upon between manufacturer and purchaser.

...means exactly what is stated, there must be agreement for marking wrench flats. If somone does this and you the purchaser did not agree, this is a nonconformance.

 

[vanmorrison]

Thank You Metenger, I appreciate your response.


What if the Code year specified in the contract does not specify the marking location or that marking on the wrench flats is prohibited? In this situation would it still be a nonconformance?

I do not understand the reason for prohibiting markings on the wrench flats (if the face also had the markings). I was rationalizing the reason they were prohibited on the wrench flats ALONE because the identification could be removed or obscured during installation and that it would be less likely if marked on the face. Is marking the flats a detriment to the nut? If this was the case wouldn't the Code prohibit it-no exceptions?

 

[vesselfab]

the markings "go away" when pipe wrench is applied to face.

shouldn't use pipe wrench you say, well poo-poo occurs.

 

[rmw]

Even when proper wrenches are used on nuts, markings on the flat faces can be obliterated.

And I have seen nuts tightened and loosened with hammers and quite effectively I might add. I learned how to do it from those so engaged and became fairly adept at it myself. Picture any markings that might have been on those nuts.

rmw