MIL-DTL-55668D
4.6.4.2 Noncompliance. No failures shall be allowed in group C inspection. If a sample unit fails to pass
group C inspection, acceptance of the product shall be discontinued until corrective action, acceptable to
the government, has been taken. After the corrective action has been taken, group C inspection shall be
repeated on additional sample units (all inspections or the inspection that the original sample failed, at the
option of the government). Groups A and B inspection may be reinstituted; however, final acceptance
shall be withheld until the group C reinspection has shown that the corrective action was successful. In
the event of failure after reinspection, information concerning the failure and the corrective action taken
shall be furnished to the cognizant inspection activity and the qualifying activity.
4.7 Test methods.
4.7.1 Visual and mechanical inspection. The finished cords shall be given a visual and mechanical
inspection for conformance to the applicable requirements of table VIII.
4.7.2 Stranded wire.
4.7.2.1 Tin-coating. The tin-coating on the conductor strands and the continuity, adherence, and finish
shall pass the applicable tests specified in ASTM B33.
4.7.2.2 Tensile strength and elongation. This test shall be performed in accordance with FED-STD-228,
method 3211.
4.7.2.3 Stranded wire resistance. The direct current resistance of conductors shall be measured after
being insulated, but prior to cabling, in accordance with FED-STD-228, method 6021.
4.7.3 Insulation and jacket tension recovery. The apparatus and procedure for tension recovery of
insulation and jacket shall be in accordance with table II, Cold tension recovery, except as specified
below.
4.7.3.1 Specimens. Specimens for tension recovery shall be tubular, taken from straight sections of the
finished cord.
4.7.3.2 Procedure. The specimen shall be stretched at room temperature to 50 percent elongation and
conditioned for 23±1 hours at the specified test temperature. At the end of the conditioning period, the
specimen shall be released and the percent recovery shall be measured at the end of one minute.
4.7.4 Testing of insulation. Properties of the insulation, as removed from finished cord, shall be
determined in accordance with ASTM D1248, except as specified below.
4.7.4.1 Tensile strength and elongation. The speed of jaw separation shall be two inches per minute.
4.7.4.2 Tubing requirements of insulation. To determine whether the extrusion process has caused
strains in the insulation, a specimen of each insulated conductor, taken from the straight section of a
finished cord, shall be looped back and then wound tightly on itself for 5 close turns, the ends securely
taped, and the specimen placed in a circulating air oven maintained at 121±1 C for a period of 602
minutes. After removal from the oven, the specimen shall show no evidence of cracking of the insulation
when examined under 3X magnification.
14
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business