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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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JOHANN MAIER has no NADCAP accreditations for HT, MTL and NDT. How are special processes followed?
QTR EN 2870H100016:
Page 10 – thread major diameter.
As per EN 2870, Table 1, note 1, thread major diameter “d max” shall be equal to D1 min – 0,025.
D1min = 10 – 0,028 = 9,972 mm
d max = 9,972 – 0,025 = 9,947 mm instead of 10 mm.
Actual values measured for major diameter are in line with d max = 9,947 mm if I am not mistaken, but the right d max shall be implemented for another production batches.
Page 12 – tension fatigue test.
I don’t understand this justification. As per ISO9152, clause 5.4.3, notes a, b, c, d and e describe all conditions to be met to not to perform tension fatigue test.
The only condition concerning EN2870 bolt is condition a), which is: “protruding head bolts of grip length < twice the nominal shank diameter”.
EN2870H100016 bolt has:
Shank diameter = 10 mm
Grip length = 16 mm
Then: 16 mm < 2×10 mm
For this reason, this test has not been performed. Could you please confirm?
In that case, since we have the same condition for tensile test on bolts, why tensile test has been done on bolts? Anyway, it is better this way! It should be preferable to maintain tensile test even if grip length is too short.
Page 18 – thread major diameter.
Thread major diameter "d max" shall be equal to D1 min – 0,025 as per EN 2870, Table 1, note 1.
D1min = 10 – 0,028 = 9,972 mm
d max = 9,972 – 0,025 = 9,947 mm instead of 10 mm.
Actual values measured for major diameter are in line with d max = 9,947 mm if I am not mistaken, but the right d max shall be implemented for another production batches.
Page 47 – hydrogen content on bolts
3 bolts have been tested for hydrogen content. Could we have these 3 results?
Many thanks in advance.
The MBR has received answers to the comments / conditions made by Julien Gauther and summarized them. The answers are checked and agreed by the MBR.
The QTR EN2870H100016 is up-dated to rev “C” and .
The up-date pages are:
Threads major diameter:
Page 10; and page 18 (input on the drawing)
and
Hydrogen content number of test samples:
Page 47 up-date and confirmation that hydro content test were performed on 3 test samples.
Tension fatigue test:
Page 12 was not changed, do to the grip length of 16mm which is smaller than 2*times the shank diameter. Tests are not required.
Dear Heinrich,
On QTR-EN2870_EN-2870H100016_rev-c_doc-2, page 10, clause 3.3.5, we have the folowing remark:
“Acc. to EN2870 Table 1 Note 1 the maximum Outer Diameter of the
thread must be equal to the maximum shaft diameter minus 0,025 mm”.
As per EN2870 Table 1, note 1, the thread major diameter is equal to D1min minus 0,025 mm. However, D1min is the minimum shaft or shank diameter, but not the maximum shaft diameter.
Page 12, clause 3.4.3: tension fatigue test is not applicable, but not for the reason stated, which is “no internal recess – parts have an external drive (BiHexagonal)”.
The right reason is the previous one you mentioned: “due to the grip length of 16mm which is smaller than 2*times the shank diameter. Tests are not required.”
Page 18: same remark as page 10.
Many thanks and have a good day,
Julien
QTR up-date performed.
New issue “rev.d” is uploaded. Changes in para 3.3.5 and Para 3.4.3 are marked in the report
Thank you very much Heinrich.
It is clear for me now.