MIL-DTL-22050E (SH)
4.2.3 Sampling for tests. Representative samples shall be taken at random from each lot that passes the
examination of 4.3.1, in sufficient quantity to conduct the conformance tests specified in 4.3.2. If the items are of
such size or shape that test specimens cannot be prepared form the, substitute sample shall be provided in the form
or a piece or pieces of rubber having dimensions appropriate to the tests required. The substitute samples shall be
certified by the contractor to be of identical material and equivalent cure to that used in the lot of finished material
offered for delivery.
4.3 Examinations and tests.
4.3.1 Visual and dimensional examination. Each of the samples taken in accordance with 4.2.2 shall be
subjected to surface examinations for identification, workmanship, dimensions, and tolerances. MIL-STD-289,
MIL-STD-407, or MLD-STD-413, as applicable to the product type, shall be used to determine and evaluate visual
defects. The dimensions shall be determined in accordance with the applicable method specified in ASTM D 3767.
4.3.2 Conformance tests. Conformance tests shall be conducted on samples selected in accordance with
4.2.4. Conformance tests shall consist of the examination and tests specified in 4.4 (see 6.3).
4.3.3 Action in case of nonconformance. If any of the samples in the conformance tests are found not to
be in conformance with the requirements of the specification, the lot which they represent shall be rejected.
4.4 Test methods.
4.4.1 Testing conditions. Unless otherwise specified herein, the testing shall be conducted at a
temperature of 80o + 9oF.
4.4.2 Tensile properties. The tensile strength and ultimate elongation shall be determined by ASTM D
412. Die III specimens that are 0.080 and + 0.010 inch thick shall be used for determinations of tensile properties.
4.4.3 Hardness. Hardness shall be determined with a Shore A durometer on specimens that are 0.500 +
0.010 inch thick and at least 1.129 inch diameter, in accordance with ASTM D 2240. The hardness readings shall
be taken within 1 second after firm contact is made between the rubber and the presser foot of the durometer.
4.4.4 Oven aging. ASTM D 573 shall be used for oven aging the test specimens as specified for the
individual tests, with the following exception: The aging period shall be 166 + 1 hours at 280o + 2oF. After the
aging period, the tensile hardness specimens shall be set aside for 16 to 96 hours at 80o + 9oF before determining the
required property.
4.4.4.1 Tensile properties after oven aging. The tensile properties after oven aging shall be determined by
the procedure specified in 4.4.2.
4.4.4.2 Hardness after oven aging. The hardness after oven aging shall be determined by the procedure
specified in 4.4.3.
4.4.4.3 Compression set after oven aging. Compression set shall be determined in accordance with ASTM
D 395 except that three 0.500 + 0.010 inch thick specimens shall be tested and the specimens shall be held at a 25
percent deflection during oven aging.
4.4.5 Immersion in hot distilled water. Test specimens for the individual tests shall be immersed in
distilled water in a covered glass jar. The jar shall be put in a container capable of withstanding an internal pressure
of 300 pounds per square inch (lb/in2). The container shall be sealed and placed in a steam autoclave and heated for
166 + 1 hours at 330o + 2oF.
4.4.5.1 Tensile properties after immersion in hot distilled water. After immersion in hot distilled water as
specified in 4.4.5, the tensile properties shall be determined in accordance with ASTM D 471 and as specified in
4.4.2. Tensile strength shall be based on the swollen cross-sectional area.
6
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business