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1.1 These reference radiographs are reproductions of original radiographs and illustrate various types and degrees of discontinuities occurring in tin bronze and related types of alloys. They are intended to provide the following:

1.1.1 A guide to the recognition of common discontinuities and their differentiation both as to type and severity level.

1.1.2 A standard nomenclature for reference in acceptance standards, specifications and drawings.

1.1.3 A source of reference radiographs from which manufacturers and purchasers may, by mutual agreement, select particular radiographs to serve as standards representing minimum acceptability. The standards so established are identified by an alphabetic defect type and severity level (or class) designation.

1.2 The original radiographs are of discontinuities in sand cast 88:8:4 Cu-Sn-Zn, "G" type, bronze alloy plates. These discontinuities are representative of those found in wide solidification range copper-tin base alloys. The following ASTM specifications illustrate alloys covered by these standards; however, it is intended that these reference radiographs also apply to related Government and commercial material specifications:

Valve bronze castings B 61 A Composition bronze or ounce metal castings B 62 B Tin bronze sand castings B 584 Leaded red brass sand castings B 584 Copper-base alloy centrifugal castings (as applicable) B 271 A Similar to MIL-B-16541. B Similar to MIL-B-16444.

1.3 The discontinuity types and severity levels represented by the reference radiographs are shown in Table 1, which also indicates the code designation for each discontinuity type.

1.4 The use of this document is not intended to be restricted to the specific energy level or to the absolute thickness limits that are contained in the document title. The title is intended to be descriptive and not restrictive. The document may be used, where there is no other applicable document, for other energy levels or thicknesses, or both, for which it is found to be applicable and for which agreement has been reached between purchaser and manufacturer.

Note 1-The reference radiographs consist of twenty-two 21/2 by 51/2-in. radiograph reproductions of low voltage X rays. Fifteen of these were made with newly developed 1-in. plate castings and seven were made with 3/4-in. plate castings used originally for documents NAVSHIPS 250-537-1 and -2. The new plate castings cover Gas Porosity. Linear Shrinkage, and Feathery Shrinkage discontinuity types.

1.5 The values stated in inch-pound units are to be regarded as the standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.