MIL-DTL-82020C(YD)
3.6 Workmanship.
3.6.1 Castings. Casting shall be smooth and true to patterns. Where dimensions do not conform
to those indicated, excess material shall be removed by grinding or other approved methods.
Chaplets shall be used only where unavoidable and shall be prepared from manganese steel as
specified in 3.3.1.1. Internal chills shall not be used. Casting shall be free of surface or internal
defects which would impair the strength or service life of the castings. Tread surfaces and
flangeway walls 1-inch (25 mm) down from treads shall be free from defects, such as shrinkage,
porosity, cracks, sand holes, gas pockets, cold shuts, or other defects unless such defects are so
small that they will be removed by the finishing grinding. Castings shall be free of twist, shall be
true to alignment, and shall not be subjected to undue straining or denting produced in
straightening. Bearing surfaces of castings shall be straight and true and free from any
imperfections which would prevent a good bearing.
3.6.1.1 Depth hardening. Rail heads of the fittings shall be hardened by flexible sheet explosive
or by hammering or pressing integrally pressed pads of suitable thickness and area to not less than
a surface Brinell hardness number of 350.
3.6.2 Welding. Surfaces of parts to be welded (see 3.7) shall be free from rust, scale paint,
grease, or other foreign matter. Welding of cast manganese steel shall be performed in
accordance with Chapter 66 of the AWS Welding Handbook and section 5 of the AREA Manual
for Railway Engineering.
3.6.2.1 Electrodes. Only austenitic, high manganese (nominal 11-14 percent Mn) or stainless
steel (nominal 14 percent Cr - 14 Mn) electrodes or semi-automatic wires shall be used. Low
phosphorus grades of manganese are recommended.
3.6.3 Cleaning. Castings shall have heads and gates removed, shall be thoroughly cleaned, and all
sand, scale, fins, and excessive rough spots removed by mechanical means before final inspection.
Heads and gates may be removed by gas or arc cutting or scarfing. Sufficient metal for
subsequent removal by grinding or machining to eliminate any detrimental effect of the heat of
cutting shall be left on the casting. Gas or arc cutting or scarfing shall be followed by mechanical
cutting or grinding operations as necessary to provide the specific contour.
3.6.4 Finish. Surface of castings shall be as shown on the applicable drawings. Faces of sliding
surfaces shall have an average roughness of 63 microinches (0.001 6 mm) as defined in
ANSI B46.1 and ANSI Y14.36.
3.7 Repair of defects. Defects may be repaired by welding in a manner similar to that described
in 3.6.2 and 3.6.2.1. Defects shall be classed and defined as in 3.7.1 and 3.7.2. Minor defects
may be repaired without permission. Repair of major defects shall not be made without
permission of the contracting officer. Manganese castings shall be welded before final heat
treatment. For major defects, manganese castings shall be re-heat treated after welding. For
minor defects, re-heat treatment of manganese casting shall be required where the location and
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