MIL-DTL-13777K
3.5.4 Polyamide covering. An extruded, clear, heat stabilized polyamide jacket with a minimum 0.003 inch
(.08 mm) average wall thickness shall be extruded over all sizes 12 AWG and smaller. Polyamide shall be in
accordance with ASTM D4066, composition A, type III, low water absorption, class E and shall conform to the
heat stability test of 4.8.2.3.1 without evidence of cracks or tears. Sizes 10 AWG and larger shall require no
covering.
3.5.5 Color code. Each insulated conductor shall be color coded in accordance with the applicable
specification sheet. The insulation shall be the base color. When specifically specified, all white color coding
may be used or natural colored insulation material with stripes (see 6.2). Limits for colored insulation shall be
in accordance with MIL-STD-104.
3.5.5.1 Color coding of polyamide covering. Where extruded polyamide coverings are used, color identification
shall be by means of helical stripes applied in the same direction over the polyamide. All materials used for
striping shall be nonconductive. When the insulating compound is colored for the base color, two colored
traces shall be used when applicable with the wider stripe indicating the first tracer. When natural color
indulation is used as the insulation compound, the base color shall be indicated by an added base stripe
(see 3.5.5.2).
3.5.5.1.1 Surface resistance. The surface resistance of the covered insulated black striped conductors shall
be 10 megohm-inches (min) initial and final values when tested in accordance with 4.8.2.4.2.
3.5.5.2 Stripe width. The width of the base color stripe (when applicable) shall not be less than 0.045 inch
(1.14 mm). The first tracer shall not be less than 0.031 inch (.79 mm) and the second tracer if required shall
not be less than 0.015 inch (.38 mm). All dimensions are perpendicular to the axis of the stripe.
3.5.5.3 Length of lay. The length of lay of the colored stripes shall conform to the following:
Diameter of covering (in.)
000 to 0.083
0.084 to .110
.111 and larger
Length of lay max. (in.)
1.00
1.500
2.000
3.5.5.4 Durability. Striping applied to the outer surface shall be capable of withstanding 250 cycles (500
strokes) of abrasive action when tested in accordance with 4.8.2.4.1. A continuous line of the colored stripe
shall not be removed.
3.5.6 Conductor shield. When the construction includes a shield, a tight-fitting, closely woven braid of tin
coated soft or drawn and annealed copper strands shall be applied over the jacket. The shield shall be applied
in such a manner as to provide at least 75 percent coverage over the construction beneath. The braid shall
consist of 36 AWG for diameters 0.250 inch (6.35 mm) or less and 34 AWG for larger sizes. Shields shall be
applied in such a manner as to preclude irregularities, breaks or other discontinuities not consistent with good
manufacturing practice. The percent coverage of the shield shall be computed as follows:
2
K = (2F - F ) x 100
F = NPd/Sin a
a = Tan (2š(D +2d) P/C)
-1
Where:
F=
Fill or space factor
K=
Percent coverage
N=
Number of strands per carrier
P=
Picks per inch of wire length
d=
Diameter of individual shield strands in inches
a=
Angle of braid with axis of cable
D=
Diameter of wire under the shield in inches
C=
Number of carriers
6
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business