MIL-DTL-11891 Track Shoe Sets, Track Shoe Assemblies, Track Shoe Pads And Track Shoe Bushings, Vehicular: ElastomerizedThis specification identifies the requirements for qualification and production control of track systems supporting U.S. Military Tracked Vehicles. This specification is intended primarily for the qualification of elastomeric compounds used in the fabrication of track and track components and to ensure that the quality and performance established at qualification is maintained throughout production. The contractor is held fully responsible for the entire assembly/component including all non-elastomeric components and fasteners.

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MIL-DTL-11891G(AT)

4. VERIFICATION

4.1 Classification of inspection. The inspection requirements specified herein are

classified as follows:

Qualification inspection (see 4.3)

First article inspection (see 4.4)

In-process inspections and tests (see 4.5.2)

Conformance inspection (CI) (see 4.5.3)

Control tests (see 4.6)

4.2 Inspection conditions. All inspections shall be performed in accordance with

conditions specified in applicable drawings, specifications, and standards.

4.3 Qualification inspection.

4.3.1 Sampling for qualification inspection. Qualification inspection shall be performed

on sample units selected in accordance with table III for bushings and table IV for track

roadwheel path and ground pad rubber which were produced with equipment and procedures

normally used in production. The test results and other inspection information will be submitted

to the Government to be used for the establishment of average values for future production

control. Established property and tolerances in tables I and II must be met by qualification

specimens subjected to applicable tests. Upon successful fabrication and qualification of all

components and tracks, contractors shall not make any compound formulation changes in either

the type or the quantity of ingredients without prior Government approval.

4.3.1.1 Bushings (unvulcanized). Samples from unvulcanized bushings shall be taken

upon final compound mixing for the performance of the following qualification tests: specific

gravity, hardness, tensile strength, elongation, tensile stress, aged properties, brittleness point,

cure meter, TGA, compression set, GC mass.

4.3.1.2 Bushings (vulcanized). The following tests will be performed on vulcanized

bushings: hardness, adhesions, bushing endurance.

4.3.1.3 Roadwheel path and ground pad (unvulcanized). Samples from unvulcanized

roadwheel path and ground pad rubber shall be taken upon final compound mixing for the

performance of the following qualification tests: specific gravity, hardness, tensile strength,

elongation, tensile stress, aged tensile strength (roadwheel path only), aged elongation (roadwheel

path only), brittleness point, cure meter, ozone resistance, TGA, and GC mass.