Purpose:

The purpose of this military standard is to prescribe the non-destructive testing acceptance criteria for the inspection of metal castings that are classified (see 1.3) in accordance with this standard.

Applicability:

Casting methods: This standard is intended to apply to all casting methods except high pressure die castings (such as the ones covered by ASTM B 85, "Aluminum Alloy Die Castings").

Casting Alloys: This standard applies to casting alloys that fall under one of the alloy families covered in tables 6 through 14 of this standard. Alloys that do not belong to any of the alloy families covered in tables 6 through 14 may be inspected to this standard in accordance with 5.3.3.2.

Classification:

Castings that are inspected in accordance with this standard are classified by classes and applicable grades. This class governs the frequency of inspection (see 6.4), while the grade controls the quality of the casting.

Classes: For design information only, castings are classified as follows:

a. 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.

b. 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.

c. Class 3. Castings not included in Class 1 or Class 2 and having a margin of safety of 200 percent or less.

d. 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 grades A, B, C or D as shown in Tables 6 through 14 for radiographic requirements, and table 4 for magnetic particle and liquid penetrant requirements. For design information only, definitions for the grades are shown below:

a. 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.

b. 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.

c. Grade C - A high quality grade of casting, or area of a casting, that can be consistently produced.

d. 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.