FED-STD-228A
Method 2021.1
18 APRIL 2014
FLEXIBILITY, ARMORED CABLE, LOW TEMPERATURE
1. SCOPE
1.1 This method is intended for use in determining the ability of armored cable to withstand bending at a
low temperature without damage.
2. SPECIMEN
2.1 The specimen should be a piece of the inspection unit of sufficient length to permit bending one
complete turn around the mandrel required in 4.2.
3. APPARATUS
3.1 The apparatus shall be as follows:
3.1.1 Mandrel of the diameter required in 4.2.
3.1.2 Wooden bar approximately 5 feet in length.
3.1.3 Cold chamber as a refrigerator or other equipment capable of maintaining the mandrel and
mounted specimen at the required temperature within ± 1°C. (2°F).
4. PROCEDURE
4.1 Unless otherwise specified in the detail specification, the specimen shall be subjected to a
temperature of -10°C ± 1°C. (14° ± 2°F) for a period of 18 ± ¼ hour.
4.2 Unless otherwise specified in the detail specification, the size of the mandrel shall be 6.5 times the
over-all diameter of the specimen.
4.3 The specimen shall be free from mechanical damage and shall not be bent or flexed until it has
reached room temperature. It shall be straightened and mounted on a wooden bar. The mounted
specimen and mandrel shall be placed in the cold chamber at the required temperature for the required
period of time. At the end of the exposure period, the specimen shall be removed from the cold chamber,
detached from the bar, and immediately bent around the mandrel at a uniform rate of 20° per second.
The specimen shall be clamped in the bent position and a visual inspection made of all its component
parts. The armor shall be opened and the material under it examined for cracking or other damage.
4.4 Flat twin wire or cable shall be bent on the minor axis of its cross section only. The minor diameter
shall be used in determining the size of the mandrel.
5. RESULTS
5.1 Unless otherwise specified in the detail specification, one specimen from each inspection unit shall
be tested.
5.2 Any cracking or other damage to the armor of other parts of the specimen shall be recorded.
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