Conditions for approval required by: Julien Gauther
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Certification of Aerospace Products to international quality Standards
Certification of Aerospace Products to international quality Standards
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What are thicknesses measured ? And where ?
It seems that Brinell Hardness test has been done instead of Rockwell test (maybe due to the fact that Rockwell is not suitable because of bolt size and/or load to be applied). EN3685 requires Rockwell.
If Brinell hardness has been done, what is the hardness conversion table used ? (HBW to HRC)
Sampling size for acceptance (EN3685, Table 8, column A). For qualification, it is 4 parts.
? Sampling for acceptance used for penetrant inspection, dimensional and visual inspections.
5 bolts tested, but for qualification, it is only 4. It seems that sampling has been done considering EN3685, Table 8 instead of EN3685, Table 4 (qualification column).
Length under head of EN3687-050022 is 22 mm. Grip length (in my opinion) corresponds to W dimension, so for this bolt, grip length is 6 mm MAX.
The condition for tensile test is: Tensile tests are not applicable to the following:
a) Protruding head bolts of grip length less than 2 D.
Thus, tensile test on these bolts should not have been done.
In this case, In such cases acceptability shall be based on the results from test bars of the same material heat treated within the same process cycle.
Anyway, sampling done is more than 4 and values are conform.
Sampling for acceptance apparently (for qualification, it is 4) for macrographic and micrographic examinations.
100% inspection for Eddy Current, which is acceptance sampling, but not qualification sampling (25 parts).
Anyway, 100% is better than 25 parts.
Vickers HV30 has been performed on bolt blanks. What is the hardness conversion table used ? (HV30 to HRC).
As per EN3685, § 5.3.2.1, cooling shall be done in air. Here, cooling has been done in nitrogen. Maybe it has been done for preventing thermal oxides.
EN3685, § 5.4.2 requires ISO 7961 test 3.9. Here, ASTM E139-11 has been used. Is there any equivalence between these standard test methods ?
Maybe it is mentioned on page 2/2 of this report, but page 2/2 is not available.