1.1本实施规程为测试（a）厚度等于薄板的薄产品提供了指导，即([∧lt；=]0.249英寸。（6.30 mm）），（b）板材、锻件和挤压件的中间厚度，对于有效的平面应变断裂韧性测试来说太薄，但对于作为板材处理来说太厚，超过0.249 in。（6.30毫米）和1至2英寸。（25至50 mm），取决于韧性水平，以及（c）试验方法E399适用的相对较厚产品。关于自上次发布以来对本规范的变更，请参阅本标准末尾的变更摘要一节。 1.2本规程解决了筛选试验的问题，认识到在大量生产批次上进行正式断裂韧性测量的复杂性和费用，并以更简单、更便宜的试验形式提供了替代方案，可在研究或生产试验实验室中进行。 1.3以英寸-磅为单位的数值应视为标准值。 1.4本标准无意解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。

1.1 This practice provides guidance for testing (a) thin products, of thicknesses equivalent to sheet that is, ([∧lt;=]0.249 in. (6.30 mm)), (b) intermediate thicknesses of plate, forgings, and extrusions, too thin for valid plane-strain fracture toughness testing but too thick for treatment as sheet, that is over 0.249 in. (6.30 mm) and up to 1 to 2 in. (25 to 50 mm), dependent upon toughness level, and (c) relatively thick products where Test Method E399 is applicable. For changes to this specification since the last issue, refer to the Summary of Changes section at the end of the standard. 1.2 This practice addresses the problem of screening tests, recognizing the complexity and expense of making formal fracture toughness measurements on great quantities of production lots, and provides alternatives in the form of simpler, less expensive tests that may be carried out either in a research or production test laboratory. 1.3 The values stated in inch-pound units are to be regarded as the standard. 1.4 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.