Method for proof load testing of nuts

[QAFitz]

I've just seen the use of an hydraulic press to perform
the required Proof Load tests of nuts (i.e., A-194,
A-563 etc.). If the cross-head speed, pressure (lbf),
time under pressure etc. are accurately measured (and
traceable to NIST etc.) and all other test parameters
meet A-370/F-606, is this method acceptable for
complying with & certifying items as meeting the
A-194/A-563 Material Specs?
If not, what paragraph(s) in the specification is
this method in violation of?

 

[Goahead]

Additional requirement are probably the fully certified identification of materials and heat treatments, and documented traceability along the whole manufacturing process up to packaging, guaranteed by complete and acceptable certificates.

http://www.welding-advisers.com/

 

[Billybaru]

I see nothing in ASTM F606 that would prohibit this method. Somewhere along the line may reference the calibration of the equipment and it may require the press to be calibrated within a tolerance of 1%. I suspect there is a load cell attached to the press. This should be capable of being calibrated to 1%.

 

[Screwman]

I agree with Billy.
The method of load application doesn't matter as long as the loads and load profiles are within specs. Fixturing needs to meet the requirements of the spec (you can buy the mandrels from Greenslade & Co.) and you load and displacement measuring cells need tracability to a certified calibration.


Dick