MIL-DTL-27500H
3.7.1.5 Braided flattened wire strands. Flat wire shields shall be braided of copper, high-strength copper alloy, or nickel alloy.
The flattened wire shall be 0.0015 inch ± 0.0004 inch (0.040 + 0.010 mm) in thickness.
3.7.1.5.1 Copper wire, flattened. Copper flattened wire shall meet the requirements of ASTM B272 except the wire shall be
made by flattening round wire.
3.7.1.5.2 Flattened high strength copper alloy flat wire. Flattened high strength copper alloy wire shall be made by flattening
round wire. The flattened wire tensile strength shall be not less than 55,000 lbf/in2 and the elongation shall be one (1) percent
minimum after flattening.
3.7.1.6 Coating of flattened wire strands.
3.7.1.6.1 Tin-coated copper flattened wire. Tin-coated copper strands before flattening shall conform to ASTM B33. Flattened
wire strands shall meet the continuity of coating test of ASTM B33. The thickness of the coating shall be 250 microinches
maximum.
3.7.1.6.2 Silver-coated copper or Silver-coated high strength copper alloy flattened wire. Silver-coated copper or silver-coated
high strength copper alloy strands before flattening shall conform to ASTM B298 Flattened wire strands shall meet the continuity
of coating requirements of ASTM B298. The thickness of coating shall be 40 microinches minimum after flattening.
3.7.1.6.3 Nickel-coated copper or Nickel-coated high strength copper alloy flattened wire. Nickel-coated copper or nickel-
coated high strength copper alloy strands before flattening shall conform to ASTM B355. Flattened wire strands shall meet the
continuity of coating requirements of ASTM B355. The thickness of coating shall be 50 microinches minimum after flattening.
3.7.2 Braid angle. The shield braid shall be a push-back type. The angle of the carriers of the braid with the axis of the cable in
woven wire shields shall be not less than 18° nor more than 40°. When the maximum calculated outer diameter (see 4.4) of the
cable beneath the braid is greater than 0.31 inches (7.9 mm), the above braid angle restriction shall not apply. In this case, the
shield shall be suitably applied to provide good push-back characteristics. For determination of braid angle, see 4.3.5.
3.7.3 Shield coverage. The shield braid shall be applied in such a manner as to provide 85 or 90 percent minimum coverage for
each individual shield (see 4.3.5) as specified by the part number (see 1.2.1.1).
3.7.4 Shield splices. If splices are used in the shield, they shall not affect the geometry of the finished cable. No more than one
carrier may be spliced at any one point in the shield.
3.7.5 Jacket. When a jacket is applied over a cable or shield, all jackets shall meet the following requirements. The jacket shall
be easily removable from the finished cable without adherence to the underlying shield or cable. Stripping time (for jacket styles 11,
12, and 22 only) shall be 5 seconds maximum when testing in accordance with 4.3.15 and shall not open more than 0.125 inch (3.18
mm). The wall thickness of the jacket shall be as specified in table V for applicable material. The thickness of the jacket between the
shields in the double shield and double jacket shall be 75 percent of the values specified in table V.
3.7.5.1 Jacket material.
3.7.5.1.1 Extruded clear polyamide. Extruded polyamide jackets shall be limited in application to cables having a maximum
calculated outer diameter (see 4.4) not greater than 0.25 inch (6.4 mm) prior to application of jacket. Extruded polyamide jackets
shall be applied concentrically and shall have a wall thickness in accordance with table V. The polyamide shall be in accordance
with ASTM D 4066 type PA 0621E22.
10
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business