MIL-N-21337
4.4.5 Classification of defects. Inspection shall be conducted for the following:
Method of
Inspection
Catagories and defects
Major -- AQL 1.5 percent
1. Runout and parallelism of faces . . . . . . . . . . . . . . See 4,5.2.1
2* Thread pitch and minor diameters . . . . . . . . . . . . Gage
3. "1?" diameter (see Tables I & 11) . . . . . . . . * SMI or gage
4. Cracks, seams, inclusions and flaws . . . . . . Visual and magnetic
particle inspection.
Minor -- AQL 4.O percent
51. "D" thickness (see Tables I & II) . . . . . . . . * SMI or gage
52* Surface roughness . . . . . . . . . . . , Visual
53. "C" outside diameter . . . . . . . . . . . . . . . . . * SMI or gage
54. Protective coating . . . . . . . . . . . . . . . . . Visual
55. Slots equally spaced within 0,006 of basic
position S., . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gage
56. Burrs or sharp edges . . . . . . . . . . . . . . . . . . . Visual
* Standard measuring instrument e.g. scale, calipers, micrometers, etc.
faces. The sample nut shall be mounted on
4.5 Tests.
a tight fitting threaded arbor, (a tapered
arbor is not acceptable for this purpose),
4.5.1 Lot acceptance tests.
and a calibrated indicator "applied against
the contact or chamfered side of the nut
4.5.1.1 Side runout and parallelism of
(see fig. 3). The thread dimensions of the
faces. Each sample nut selected in accord-
arbor employed shall conform to the thread
ance with 4.3.1 shall be subjected to a run-
data and tolerances specified in tables I and
out and parallelism test in accordance with
II for the applicable type and class of nut.
the procedures of 4.5,2.1 to determine con-
formance to the tolerance specified in fig-
ures 1 or 2, as applicable.
4.5.2.2 Composition and hardness. The
test procedures for the composition and
4.5.1.2 Chemical composition. Sample nuts
hardness of nut shall be as described in FED.
selected in accordance with 4.3.2.1 shall be
TEST METHOD STD. No. 151.
tested for the composition requirements of
3.1.1, 3.1.2, or 3.1.3, as applicable, and in
4.6 Rejected lot. A rejected lot maybe re-
accordance with test procedures of 4.5.2.2.
submitted for Government acceptance in ac-
cordance with the provisions of Standard
4.5.1.3 Hardness. Sample nuts selected in
MIL-STD-105.
accordance with 4.2,2.2 shall be tested for
the hardness requirements of 3.7.1, 3.7.2, or
5. PREPARATION FOR DELIVERY
3.7.3, as applicable, and in accordance with
test procedures of 4.5.2.2.
5.1 General. Nuts shall be prepared for
shipment in accordance with Level A, Level
4.5.2 Test and inspection procedures.
B, or Level C, as specified in the contractor
order (see 6.2).
4.5.2,1 Side runout and parallelism of
7