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)

requirements of this specification. The molding pressure will be set and be maintained by the

manufacturers to assure production of defect free components that will meet all specification

requirements. The values for vulcanization time, pressure and temperature shall be identified in

the Process Fingerprint Plan (see 3.3).

4.5.2.5 Failures. Control failures are indicated by a deficiency discovered at any process

control point (process parameter controls) , during testing identified in tables III and IV, or

during product inspections (product characteristic controls).

4.5.2.5.1 Process control failures. Process control failures are indicated by a deficiency

discovered at the process control point during the inspection parameters identified in 4.5.1.1.1. A

failure shall require the contractor to take corrective action to eliminate the problem and prevent

its recurrence. Contractors shall correct failures or deficiencies to preclude production of

defective products.

4.5.2.5.2 Product control failures. Product control failures shall be determined upon

performance of inspections/tests listed in tables III and IV. Failures which are discovered in

mixed, extruded and vulcanized compounds shall be separated by screening preceding and, if

necessary, subsequent runs until all defective materials are found and rejected. Contractors can

retest two additional specimens out of the same deficient runs to confirm failure to meet

requirements. If these last two specimens pass the test, then that control test is considered to be

met. Failure of either of the two additional tests shall result in the rejection of all defective

products.

4.5.2.6 Data comparison. Comparative data obtained from both in-process inspections

and control tests shall be compared with data submitted in connection with qualification approval.

Variations in excess of tolerance (see section 3) shall be evidence of change of materials, formula,

or manufacturing procedure, and shall be cause for rejection.

4.5.3 Conformance inspection (CI).

4.5.3.1 Sampling for conformance inspection. The samples for CI examination shall be

randomly selected from the inspection lot in accordance with table V.

4.5.3.1.1 Lot formation. Unless otherwise specified (see 6.2), a lot shall consist of all

items submitted at one time, of one part number, manufactured under identical conditions from an

identifiable production period not to exceed one work shift of a day's production from one

manufacturer and from one production facility.