ASTM A997/A997M-23

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: A997/A997M − 23
Standard Practice for
Investment Castings, Surface Acceptance Standards, Visual
1
Examination
This standard is issued under the fixed designation A997/A997M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 2.1.2 nonrelevant indication, n—an indication that is caused
by a condition or type of discontinuity that is not rejectable.
1.1 This practice covers the acceptance criteria for surface
inspection of investment castings by visual examination. 2.1.3 positive metal, n—raised metal on the casting surface,
usually associated with the breakdown of the mold and its
1.2 This practice is expressed in both inch-pound units and
replacement with the casting metal.
in SI units; however, unless the purchase order or contract
specifies the applicable M-specification designation (SI units),
2.1.4 surface pit, n—a nonlinear depression in the cast
the inch-pound units shall apply. surface whose length is less than three times its width. Surface
pits may be the result of gas or non-metallic inclusions.
1.3 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
2.1.5 surface roughness, n—a measure of surface texture,
each system may not be exact equivalents; therefore, each
usually determined by the use of a comparator or calibrated
system shall be used independently of the other. Combining
device.
values from the two systems may result in nonconformance
with the standard.
3. Ordering Information
1.4 This standard does not purport to address all of the
3.1 The inquiry or order should specify the following
safety concerns, if any, associated with its use. It is the
information:
responsibility of the user of this standard to establish appro-
3.1.1 Acceptance Level—More than one acceptance level
priate safety, health, and environmental practices and deter-
may be specified for different surfaces of the same casting (see
mine the applicability of regulatory limitations prior to use.
Section 4),
1.5 This international standard was developed in accor-
3.1.2 If any types of discontinuities are unacceptable,
dance with internationally recognized principles on standard-
3.1.3 Casting surfaces to be examined,
ization established in the Decision on Principles for the
3.1.4 Number of castings to be examined, and
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical 3.1.5 Additional acceptance criteria as applicable to all or
portions of the casting surface.
Barriers to Trade (TBT) Committee.
2. Terminology
4. Acceptance Criteria
2.1 Definitions of Terms Specific to This Standard:
4.1 Levels of acceptance for visual inspection are listed in
2.1.1 linear discontinuity, n—a discontinuity whose length
Table 1.
is equal to or greater than three times its width. Cracks and cold
shuts are examples of linear discontinuity. 4.2 Parts shall not exhibit any linear discontinuities.
4.3 Surface roughness and surface pits that will be removed
1
This practice is under the jurisdiction of ASTM Committee A01 on Steel,
by machining are considered acceptable.
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
A01.18 on Castings.
4.4 Surface discontinuities not covered in this practice shall
Current edition approved March 1, 2023. Published March 2023. Originally
be a matter of agreement between the purchaser and the
approved in 1998. Last previous edition approved in 2018 as A997 – 08 (2018).
DOI: 10.1520/A0997_A0997M-23. manufacturer.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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A997/A997M − 23
A,B
TABLE 1 Visual Inspection Acceptance Criteria
Surface Feature Level II Level III Level IV
C,D,E
Surface Pits 0.030 in. [0.76 mm] 0.060 in. [1.52 mm] 0.060 in. [1.52 mm]
diameter by 0.015 in. diameter by 0.030 in. diameter by 0.030 in.
[0.38 mm] deep with [0.76 mm] deep with [0.76 mm] deep with
2 2 2
no more than 1 per in. no more than 1 per in. no more than 4 per in.
2 2 2
[645 mm ] [645 mm ] [645 mm ]
D,E
Positive Metal 0.060 in. [1.52 mm] 0.125 in. [3.18 mm] 0.125 in. [3.18 mm]
diameter by 0.015 in. diameter by 0.030 in. diameter by 0.030 in.
[0.38 mm] high with [0.76 mm] high with [0.76 mm] high with
2 2 2
...