2.2.5.3
[Disposition of Patterns, Core Boxes, and Templates
Boxes and crates for the packing and shipment of patterns, core boxes and
templates shall be substantially made and put together with screws so that
they can be used several times. Each box and crate shall be plainly marked
to indicate its contents. All patterns, core boxes and templates
[including those loaned to the Contractor by the Government] used shall be
thoroughly cleaned, crated and delivered in first-class condition with a
list of same in duplicate to [_____] before final payment is made. The
Contracting Officer reserves the right to withhold payment for final parts
made from any pattern until such pattern is delivered. Patterns and core
boxes shall be varnished and all templates given a coat of an approved
paint before being crated. Any pattern, core box or template lost in
shipment or damaged by the Contractor shall be replaced by the Contractor
without charge to the Government.]
2.2.6
Castings
Each casting shall bear cast or stamped mark numbers. Castings weighing
more than 225 required kilograms 500 required pounds shall also bear cast
or stamped heat numbers. Deviations from the dimensions of castings shown
shall not exceed amounts that will impair the strength of castings by more
than 10 percent as computed from the dimensions shown. Dimensions of
castings shown on approved detail drawings shall be finished dimensions.
Castings that are warped or otherwise distorted or that are oversize to an
extent that will interfere with proper fit with other parts of the
machinery or structure will be rejected. The structure of metal in
castings shall be homogeneous and free from excessive nonmetallic
inclusions. Excessive segregation of impurities or alloys at critical
points in castings will be cause for rejection. Repairs to castings shall
not be made prior to approval. Minor surface imperfections not affecting
the strength of casting may be welded in the "green" if approved. Surface
imperfections shall be considered minor when the depth of the cavity
prepared for welding is the lesser of 20 percent of the actual wall
thickness or 25 mm 1 inch. Defects other than minor surface imperfections
may be welded only when specifically authorized in accordance with the
following requirements:
a. The defects have been entirely removed and are judged not to affect
the strength, use or machineability of the castings when properly
welded and stress relieved.
b. The proposed welding procedure, stress relief and method of
examination of the repair work have been submitted and approved.
2.2.7
Machine Work
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NOTE: Paragraphs, PIN HOLES, GEARS, SHAFTING, and
BEARINGS, should be deleted when the details
specified are provided in the machinery section.
**************************************************************************
Tolerances, allowances and gauges for metal fits between plain,
non-threaded, cylindrical parts shall conform to ASME B4.1 for the class of
fit shown or required unless otherwise shown on approved detail drawings.
Where fits are not shown they shall be suitable as approved. Tolerances
for machine-finished surfaces designated by non-decimal dimensions shall be
SECTION 05055A
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