Table 3-2. Test Loads
Endless Ring Bungee
3-6.Gaskets and Packings. The methods of identification, military classifications, types, uses, and storage of gaskets
and packing materials are presented in the following paragraphs.
Gasket and Packing Types. Gasket and packing material types and uses are described in the following
(1) Synthetic rubber and cork gasket material MIL-C-6183. This material is available in soft, medium, and firm
grades it is classified as aromatic fuel and oil resistant.
(2) Synthetic rubber gasket material MIL-R-6855. This material is classified as fuel, oil, and non-oil-resistant.
Use oil-and non-oil-resistant gaskets with acrylic plastics. This material is available in grades 40, 60, and 80, each of
which corresponds to a durometer hardness value.
(3) Cork sheet and gasket material Federal Specification HH-C-576. This cork composition is available in sheet
and gasket. Light composition is recommended for use as a cushion between glass and metal. Medium-light
composition is recommended for use on cover plates and gear cases. Medium-heavy composition is recommended for
uses similar to medium-light composition where less than 1/16-inch thickness, and greater tensile strength are required.
Heavy composition is recommended for use with transformers, oil-filled electrical equipment, and as a packing or bearing
seal for rotating members.
(4) Synthetic or natural rubber gasket and packing material Federal Specification HH-G-156
. This material is
used for all types of packings and gaskets except hatches and watertight and airtight doors. It is classified as soft,
medium, and hard, and is available in sheets, molded shapes, strips, and fabricated gaskets.
O-ring splicing and O-ring assortment kits do not meet the specific requirements for O-
ring usage on aviation equipment and are not authorized for use on Army aircraft. Use
of unauthorized O-rings may compromise the integrity and safety of equipment and
Use MS28775 O-ring only where specified. Leakage will occur below -65 °F (-540C).