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Certification of Aerospace Products to international quality Standards
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Locking torque – 15 cycles test: EN2647-050 is a self-locking nut with 900 MPa strength class.
Why do we have 4,7 N.m for seating torque in QTR? It should be 3,9 N.m (900 MPa UTS).
For locking torque test, test bolt is made out of steel, cadmium plated and with 1100 MPa UTS according to QTR. As per ISO7481, clause 3.9.1, sub-clause B), note 2), sub-note ii), test bolt shall have a strength class identical to that of nut under test.
Many thanks in advance,
Best regards.
Hello M. Gauther,
On behalf of Mrs Genevieve Lacombe, see below her explanations to your comments :
Locking torque – 15 cycles test: EN2647-050 is a self-locking nut with 900 MPa strength class.Why do we have 4,7 N.m for seating torque in QTR? It should be 3,9 N.m (900 MPa UTS).
==> See QTR8908A updated enclosed . It was a typo .
For locking torque test, test bolt is made out of steel, cadmium plated and with 1100 MPa UTS according to QTR. As per ISO7481, clause 3.9.1, sub-clause B), note 2), sub-note ii), test bolt shall have a strength class identical to that of nut under test.
==> After checking , test bolts used had a strength class of 900 MPa ; so same strength class as the nut, so the QTR 8908A was updated. It was also a typo.
Good receipt of these replies,
Regards,
Nadege Richard
Hello Mrs. Richard, Mrs. Lacombe,
Many thanks for updating QTR (8908A-5JPHO80035M-ISO5858) uploaded in “Additional documents”.
I am happy with this update, so, approved on my side.
Best regards.