ASTM A997-08(R2018) pdf free download

ASTM A997-08(R2018) pdf free download.Standard Practice for Investment Castings, Surface Acceptance Standards, Visual Examination
1. Scope
1.1 This practice covers the acceptance criteria for surface inspection of investment castings by visual examination. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 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 appro- priate safety, health, and environmental practices and deter- mine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Terminology
2.1 Definitions of Terms Specific to This Standard: 2.1.1 linear discontinuity, n—a discontinuity whose length is equal to or greater than three times its width. Cracks and cold shuts are examples of linear discontinuity.2.1.2 positive metal, n—raised metal on the casting surface, usually associated with the breakdown of the mold and its replacement with the casting metal. 2.1.3 surface pit, n—a nonlinear depression in the cast surface whose length is less than three times its width. Surface pits may be the result of gas or non-metallic inclusions. 2.1.4 surface roughness, n—a measure of surface texture, usually determined by the use of a comparator.
3. Ordering Information
3.1 The inquiry or order should specify the following information: 3.1.1 Acceptance Level—More than one acceptance level may be specified for different surfaces of the same casting (see Section 4), 3.1.2 If any types of discontinuities are unacceptable, 3.1.3 Casting surfaces to be examined, 3.1.4 Number of castings to be examined, and 3.1.5 Additional acceptance criteria as applicable to all or portions of the casting surface.
4. Acceptance Criteria
4.1 Levels of acceptance for visual inspection are listed in Table 1. 4.2 Parts shall not exhibit any linear discontinuities. 4.3 Surface roughness and surface pits that will be removed by machining are considered acceptable. 4.4 Surface discontinuities not covered in this practice shall be a matter of agreement between the purchaser and the manufacturer.