Synthetic Rubber Hose
Synthetic rubber hose has a seamless synthetic
rubber inner tube covered with layers of cotton and
wire braid, and an outer layer of rubber impregnated
cotton braid. The hose is provided in low-, medium-,
and high-pressure types.
Synthetic rubber hose (if rubber-covered) is
identified by the indicator stripe and markings that are
stencilled along the length of the hose. The indicator
stripe (also called the lay line because of its use in
determining the straightness or lie of a hose) is a
series of dots or dashes. The markings (letters and
numerals) contain the military specification, the hose
size, the cure date, and the manufacturer’s federal
supply code number. This information is repeated at
intervals of 9 inches. Refer to figure 5-2.
Size is indicated by a dash followed by a number
(referred to as a dash number). The dash number does
not denote the inside or outside diameter of the hose.
It refers to the equivalent outside diameter of rigid
tube size in sixteenths (1/16) of an inch. A dash 8 (-8)
mates to a number 8 rigid tube, which has an outside
diameter of one-half inch (8/16). The inside of the
hose will not be one-half inch, but slightly smaller to
allow for tube thickness.
The cure date is provided for age control. It is
indicated by the quarter of the year and year. The year
is divided into four quarters.
1st quarter — January, February, March
2d quarter — April, May, June
3d quarter — July, August, September
4th quarter — October, November, December
The cure date is also marked on bulk hose
containers in accordance with Military Standard 129
(MIL-STD-129).
Synthetic rubber hose (if wire-braid covered) is
identified by bands wrapped around the hose at the
ends and at intervals along the length of the hose.
Each band is marked with the same information
(fig.5-2).
are its operating temperature range, its chemical
inertness to all fluids normally used in hydraulic and
engine lubrication systems, and its long life. At this
time, only medium-pressure and high-pressure types
are available. These are complete assemblies with
factory-installed end fittings. The fittings may be
either the detachable type or the swaged type. When
failures occur, replacement must be made on a
complete assembly basis.
Teflon® hose is identified by metal bands or
pliable plastic bands at the ends and at 3-foot
intervals. These bands contain the hose military
specification number, size indicated by a dash (-) and
a number, operating pressure, and the manufacturer’s
federal supply code number. Refer to figure 5-2.
HOSE ASSEMBLY HARDWARE
Hose fittings are designed and constructed in
accordance with military specifications and military
standard drawings for particular hose configurations
and operating pressures.
Fittings designated by a military standard
drawing number have a particular dash number to
indicate size.
The fitting dash number does not
designate a size in the same manner as a hose dash
number. The fitting dash number corresponds to the
dash number of the hose so that both will match at the
critical dimensions to form a hose assembly.
Materials used in the construction of fittings vary
according to the application.
Materials include
aluminum, carbon steel, and corrosion-resistant steel.
Fittings that qualify under one military document may
be produced by several manufacturers. Two methods
or styles are used to secure the hose fitting on to the
hose. They are the reusable and swage or crimp style.
Reusable Style
Teflon® Hose
The preferred reusable style has modified internal
threads in the socket to grip the hose properly. The
The Teflon® hose is made up of a tetrafluoro-
fitting can be disassembled from a hose assembly and
ethylene resin, which is processed and extruded into
reused on another hose, provided it passes an
tube shape to a desired size. It is covered with
inspection for defects.
Reusable style fittings are
stainless steel wire, which is braided over the tube for
authorized replacement fittings for replacement hose
strength and protection. The advantages of this hose
assemblies.
5-2
