MIL-DTL-442G
TABLE VII. Insulation physical property tests for dumbbell specimens.
Tests
Test method specification
Tensile strength
Elongation, ultimate
Tension set
Accelerated aging
FED-STD-601 method 7001
4.4.8.1 Vinyl polymer compound (class 1). The color of the insulation material shall be visually
checked, and the fungus resistance shall be tested in accordance with ASTM-G21.
4.4.8.1.1 Heat resistance. Heat resistance shall be verified by the "Blocking Test" method, which
shall be conducted in accordance with ASTM-D3354 when exposed to a temperature of 70±1 °C for 48
hours with an applied pressure of .33 psi. The test specimens shall be cut from the sheet used to obtain
the tensile strength specimens of table VII.
4.4.8.2 Synthetic rubber compound (class 2) aging. The synthetic rubber compound shall be
subjected to the "Oxygen Pressure Test", ASTM-D572, after being exposed to 70±1 °C under sustained
oxygen pressure of 290 to 310 psi for a minimum of 96 hours. The specimen shall then be tested to
4.4.8.3 Natural rubber compound (class 3) aging. This material shall be subjected to the "Oxygen
Pressure Test", ASTM-D572, after being exposed to 70±1 °C under sustained oxygen pressure of 290 to
310 psi for a minimum of 96 hours. The specimen shall then be tested to verify its table III physical
properties using the applicable test method of table VII.
4.4.9 Finished cable.
4.4.9.1 Dielectric strength. This test shall be performed in accordance with method 6111 of
4.4.9.2 Insulation resistance. This test shall be performed at a temperature of 15.6 °C in accordance
with method 6031 of FED-STD-228. This test shall be performed as soon as possible after the dielectric
strength test.
4.4.9.3 Flexibility. This test shall be performed on a specimen of finished cable approximately
7.5 inches (191 mm) long. The specimen shall be in a non-flexed position while exposed to the
temperatures specified in 3.4.3. After thermal equilibrium is reached, a 1.0 inch (25.4 mm) mandrel shall
be securely clamped at both ends in a horizontal position to prevent rotation and the specimen wrapped
twice around the mandrel. An 11.023 pound (5 kilogram) weight shall be suspended from one end of the
specimen from the mandrel. The two turns of the specimen shall be completely in contact with the
mandrel prior to releasing the weight so that the specimen will be kept taut when unwinding. The free
end shall not be longer than .5 inch (12.7 mm) to permit rapid unwinding of the specimen to occur from
the mandrel. The mandrel shall be positioned at sufficient height to permit the specimen to drop free after
unwinding from the mandrel. The specimens and test equipment shall be maintained at the specified
temperature during the test, and the specimen shall be left undisturbed at that temperature for 5 minutes
thereafter. The specimens shall then be visually examined for any cracks, chips, or other damage. Note:
A clamp is needed to suspend the weight from the specimen, since at low temperatures the surface of the
coating becomes too hard to permit any other type of attachment to be effective. For this purpose, a
heavy-duty battery clip, Number 21 Mueller Universal battery clip, or its equivalent, has been satisfactory
in the past.
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