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|  MIL-W-50504A (AR)
3.3 Metal defects. The components shall be free of surface
defects, cracks, pits, cold shuts, hot tears, blow holes, scaling,
and other similar defects.
3.4 Hardness test.
3.4.1 Nose, malleable iron. Each nose casting from a sample
shall be subjected to a hardness test with a Brinell Hardness Tester.
The sample, 10 percent minimum, representative of extreme furnace
environment, shall be selected from each heat treat batch when a
batch type furnace is used for final heat treatment. When a
continuous type furnace is used for final heat treatment, from which
a 10 percent minimum 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 hereinafter
prescribed. The test shall be performed as specified in 4.5.2 using
equipment in accordance with 4.4.4.
3.4.2 Nose, ductile iron. Each nose casting from a sample
shall be subjected to a hardness test with a Brinell Hardness
Tester . The-sample shall be 1.5 percent minimum, representative of
extreme furnace conditions. When a continuous type furnace is used
for final heat treatment, a sample shall be 1.5 percent of the
castings completing heat treatment. If boxes or baskets are used
which contain approximately 70 castings, one casting from each box
shall be tested. A heat treat batch will be considered a quantity
of castings not to exceed 8 hours production. The test shall be
performed as specified in 4.5.2 using equipment in accordance with
4.4.4. The lot may be reheat treated to attain specifications and
drawing requirements.
3.4.3 Base, malleable iron. Each base casting from a sample
shall be subjected to a hardness test with a Brinell Hardness
Tester . The sample, 10 percent minimum, representative of extreme
furnace environment, shall be selected from each heat treat batch
when a batch type furnace is used for the final heat treatment.
When a continuous type furnace is used for final heat treatment,
from which a 10 percent minimum 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 hereinafter
3
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