Description / Abstract:
Purpose
This specification establishes nondestructive testing methods,
sampling frequency, and acceptance criteria for the inspection of
metal castings.
Application
This specification has been used typically for structural
castings, but usage is not limited to such applications.
Casting Methods
This specification is intended to apply to all casting methods
except high pressure die castings. See 8.2.
Casting Alloys
This specification is intended to apply to all casting alloys
covered in Tables 6 through 14. Other alloys may be inspected to
this standard as described in 3.4.3.2 using criteria specified by
the cognizant engineering organization.
Classification
Castings that are inspected in accordance with this
specification are designated by classes and applicable grades. The
"Casting Class" governs the frequency of inspection (See 3.1 and
4.3), while the "Casting Grade" controls the acceptance criteria.
See 3.1 and 3.4.
Classes
Class 1 - A casting, the single failure of which would endanger
the lives of operating personnel, or cause the loss of a missile,
aircraft, or other vehicle.
Class 2 - A casting, the single failure of which would result in
a significant operational penalty. In the case of missiles,
aircraft, and other vehicles, this includes loss of major
components, unintentional release or inability to release armament
stores, or failure of weapon installation components.
Class 3 - Castings not included in Class 1 or Class 2 and having
a margin of safety of 200 percent or less.
Class 4 - Castings not included in Class 1 or Class 2 and having
a margin of safety greater than 200 percent.
Grades
Castings, or sections of a casting, shall be of the following
grades:
Grade A - The highest quality grade of casting, or area of a
casting, with minimum allowable discontinuities and very difficult
to produce except in local areas.
Grade B - The second highest quality grade of casting, or area
of a casting, which allows slightly more discontinuities than Grade
A, and difficult to produce, except in local areas.
Grade C - A high quality grade of casting, or area of a casting,
that can be consistently produced.
Grade D - The lowest quality grade of a casting, or area of a
casting, that is easily produced and is used primarily for low
stress or noncritical areas adjacent to the higher graded
areas.