MIL-W-14969 (MU)
4.3,3.2.2 Malleable Iron Base Casting Hardness Test - Major
Defect - Code No. 02007. - To insure compliance with the mechanical
properties requirements, each base casting from a sample shall be
subjected to a hardness test with a Brinell Hardness Tester. The
sample, a 10% minimum, representative of extreme furnace environment,
shall be selected from each heat treat batch of 1000 or fraction
thereof when a batch type furnace is used for the final heat treat-
ment. When a continuous type furnace is used for final heat treat-
ment, from which a 10% min. sample will also be selected, a heat
treat batch will be considered a quantity of castings not to exceed
4 hours production. The castings which constitute the sample shall
be collected at regular continuous intervals throughout the 4 hour
cycle. The heat treat batch thus constituted shall form the basis for
selecting sample castings for the tension test here-in-after pre-
scribed. The hardness test shall be performed on the approximate
center of the bottom of the castings, The test shall be performed
as specified in 4.4.1 using equipment in accordance with 4.3.4.
4.3.3.3 Tension Test
4.3,3.3.1 Tension Test on Nose (Ductile Iron) - Major Defect -
Code No. 01004. - The hardest and softest casting representing the
days' heat treat production as determined in 4.3.3.2.1 shall be
subjected to the test specified in 4.4.3 using equipment in accord-
ance with 4.3.4. Failure of any test specimen to comply with the
applicable physical properties requirements shall be cause for
rejection of the days' heat treat production represented by the
specimens.
4,3.3.3.2 Tension Test on Base. Major Defect - Code No. 02008.
When malleable iron is used two base castings from each heat treat
batch; one of the hardest and one of the softest as determined by
4.3.3.2.2 shall be subjected to the tension test In accordance with
4.4.4, to determine compliance with the mechanical properties re-
quirements of the applicable drawing. When steel bases are used,
two bases from each heat treatment or stress relieved batch of 5000
or fraction thereof shall be subjected to the tension test. Failure
of any specimen to comply shall be cause for rejection of the batch
represented by the specimen. The test shall be performed as speci-
fied in 4.4.4 using equipment in accordance with 4.3,4.
4.3.3.4 Hydrostatic Test, - Critical defect - Code No. 03031 -
Each metal parts assembly shall be subjected to the required constant
internal hydrostatic pressure to determine compliance with re-
quirements specified on dwg. 9238883. Failure of any assembly to
comply shall be cause for rejection of the assembly. Metal parts
assemblies which comply shall be stamped with the letter "H" as
indicated on the assembly drawing. The test shall be performed
as specified in 4.4.5 using equipment in accordance with 4.3.4.
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