MIL-DTL-26202E
3.5.8.3 Fasteners. On unidirectional and bidirectional units all bolt heads shall be below the external
surface of the housing, and a counterbore shall be provided for the bolt holes in the top of the housing
so that a standard l/2-inch socket wrench can be used. The depth of the counterbore in each of the
six holes shall be such that the specified bolts will not bottom on the gasket used between the base
and the inner rings.
3.5.8.3.1 All bolts, nuts, and fasteners shall be corrosion resistant steel. The bolts used on
unidirectional and bidirectional lights for bolting the clamp ring to the base shall be size 3/8-16, hex
head self-sealing. The thickness of the hex head shall not exceed 15/64 inch and the hex head shall
be suitably accommodated by a standard 9/16-inch socket wrench. The bolts used for bolting the
housing to the locator ring shall be 5/16-18, hex head, equipped with self-sealing washers and
threaded high enough for tightening the housing to the locator ring. The thickness of the hex plus
washer shall not exceed 15/64 inch, and the hex head shall be suitably accommodated by a standard
1/2 inch socket wrench. For omnidirectional lights, the bolts used for bolting the housing to the base
shall be 3/8-16 hex head equipped with self-sealing washers. All bolts, nuts, washers, and fasteners
shall be furnished with the light.
3.5.8.4 Ring assembly. The housing of unidirectional and bidirectional lights shall be designed to be
bolted and held in place upon a base by means of a locator ring and clamp ring arrangement. The
ring assembly shall be provided so that the light can be properly aimed at initial installation and that
relamping can be accomplished without the necessity for re-aiming the light. The housing shall bolt
directly to the locator ring which shall be held securely on the base when the clamp ring is bolted to
the base.
3.5.8.4.1 The locator ring and the clamp ring shall be in accordance with the applicable MS.
3.5.8.5 Prisms. Optical systems shall contain clear glass reflecting prisms that will accept vertical
light from the lamp and redirect the light into essentially horizontal beams that will conform to the
specified intensity distribution requirements. All optical components shall be so designed and
mounted that they are permanently and accurately aimed with no aiming necessary or possible during
installation. The design shall be such that any parts removed can be replaced only in the correct
position. Optical systems using metal reflectors and glass windows in lieu of solid glass prisms are
not acceptable on unidirectional and bidirectional lights.
3.5.8.5.1 A gradually sloped recess shall be provided in front of each prism to improve the vertical
spread of the beams. When the bottom of the prism of a class B light is masked out to the height at
which water would stand in the recess, the reduction in light output at any angle shall not exceed 15
percent for class B lights and 30 percent for class BB lights of that obtained when the bottom of the
prism is not masked. The external surface of the exit window shall be smooth.
3.5.8.5.2 High quality workmanship, methods, and materials shall be used in processing the prisms.
The reflecting surface shall be provided with a high quality coating of evaporated aluminum which is
protected with a suitable coating. All prisms shall be uniform and shall not require individual
adjustment when installed by production methods.
3.5.8.6 Lampholder. A lampholder shall be suspended from the housing and shall securely and
accurately position the lamp. The holder shall be so designed as to permit easy relamping after the
housing has been lifted out of the base, without disturbing the color filter or any other elements of the
optical system. The holder shall be indexed to prevent improper assembly and shall position the
lamp so that the beams emitted by the reflecting prisms are wider in the horizontal plane than in the
vertical plane. The material for the lampholder shall be corrosion resistant steel and capable of
withstanding the temperature developed within the light. All screws, bolts, nuts, washers, and clips
shall be corrosion resistant steel.
6
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business