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Conditions for approval required by: Julien Gauther
Certification of Aerospace Products to international quality Standards
Certification of Aerospace Products to international quality Standards
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In QTP, for hardness testing, it is written:
“27 HRC TO 44 HRC ISO 7481 (27HRC TO 41HRC, WHICH CORRESPONDS WITH 279 HV5 TO 402 HV5)”
This conversion into HV values is correct (ASTM A370, table 2 I guess), but why do we have 41 HRC and not 44 HRC?
As per ASTM A370 table 2, 27 to 44 HRC corresponds to 279 HV to 434 HV.
In Test Report (called QTR), hardness requirement is from 280 HV5 to 430 HV5, which is in line with 27 to 44 HRC.
FPI: mfg batch size is 3048 nuts.
As per EN3152 tables 3 and 4, discontinuities are considered major defects with AQL=0,065% (table 3).
Thus, sampling shall be 200 parts (table 4, we have a down arrow marked against sampling range from 1201 to 3200 parts and by considering AQL=0,065%).
In Test Report, we have only 125 FP inspected.
Reusability test – 3 cycles:
In Test Report, minimum breakaway torque is 0,8 N.m for all cycles.
As per EN3152, minimum breakaway torque for first cycle of three cycle test is 1,3 N.m and 0,8 N.m for the second and third cycles of three cycle test.
In PFC, material specification is SAM0049 whereas on ASD-CERT website, for qualification 999, we have SAM0044. Which one is correct?
Many thanks in advance,
Best regards.
In QTP, for hardness testing, it is written:
“27 HRC TO 44 HRC ISO 7481 (27HRC TO 41HRC, WHICH CORRESPONDS WITH 279 HV5 TO 402 HV5)”
This conversion into HV values is correct (ASTM A370, table 2 I guess), but why do we have 41 HRC and not 44 HRC?
As per ASTM A370 table 2, 27 to 44 HRC corresponds to 279 HV to 434 HV.
In Test Report (called QTR), hardness requirement is from 280 HV5 to 430 HV5, which is in line with 27 to 44 HRC.
• Reaction Howmet: It is a typo in the QTP, a line was not cancelled. See the updated QTP, revision A in the report).
FPI: mfg batch size is 3048 nuts.
As per EN3152 tables 3 and 4, discontinuities are considered major defects with AQL=0,065% (table 3).
Thus, sampling shall be 200 parts (table 4, we have a down arrow marked against sampling range from 1201 to 3200 parts and by considering AQL=0,065%).
In Test Report, we have only 125 FP inspected.
• Reaction Howmet: Agree sampling was performed on 125 parts because our interpretation of the table 4 was the following for batch size between 1201 and 3200 sampling size is 125 parts (see sampling highlighted). It seems that it is a bad interpretation.
Reusability test – 3 cycles:
In Test Report, minimum breakaway torque is 0,8 N.m for all cycles.
As per EN3152, minimum breakaway torque for first cycle of three cycle test is 1,3 N.m and 0,8 N.m for the second and third cycles of three cycle test.
• Reaction Howmet: Agree but our template for TR doesn’t permit us to write the 2 requirement values, so we write only the value of the second and third cycles tests. Values measured during the three cycle tests are all in line with all requirements. I admit that our TR template is not very friendly but we cannot modify it because this template is shared with other entity from Howmet.
In PFC, material specification is SAM0049 whereas on ASD-CERT website, for qualification 999, we have SAM0044. Which one is correct?
• Reaction Howmet: SAM0044 is correct. The Flow chart was updated with the correct specification number. See the updated Flow Chart, revision A in the report.
I agree with all these detailed answers and updated documents.
Many thanks for this job.
For the future, please take into account the right sample size for NDT:
“As per EN3152 tables 3 and 4, discontinuities are considered major defects with AQL=0,065% (table 3).
Thus, sampling shall be 200 parts (table 4, we have a down arrow marked against sampling range from 1201 to 3200 parts and by considering AQL=0,065%).
In Test Report, we have only 125 FP inspected.
• Reaction Howmet: Agree sampling was performed on 125 parts because our interpretation of the table 4 was the following for batch size between 1201 and 3200 sampling size is 125 parts (see sampling highlighted). It seems that it is a bad interpretation.”
Approved on my side.
Best regards.