1.1 本规范涵盖了能够指示带帽螺钉、螺栓、锚固件和螺柱中指定螺栓张力的碳钢和合金钢可压缩垫圈型直接张力指示器（DTI）的要求。 1.2 英寸尺寸的直接张力指示器 1. / 4. 到2 1. / 2. 英寸和公制尺寸M6和M72。 1.3 直接张力指示器有两种类型和四个等级的英制紧固件，即5、8、55和105级，以及两个性能等级的公制紧固件，分别为8.8和10.9级，它们在给定间隙下的压缩载荷要求不同（见 表1 和 表2 )。 1.3.1 1型DTI适用于相对较小的轴承表面。类型1 DTI可用于5级和8级，它们在规定间隙处显示的张力大小不同（参见 表1 和 表3 )。 1.3.2 2型DTI适用于相对较大的轴承表面。类型2 DTI可用于55级和105级，它们在规定间隙处显示的张力大小不同（参见 表1 和 表3 )。 1.4 直接张力指示器用于安装在螺栓或带帽螺钉头、六角螺母下，或靠在硬化垫圈或其他平坦硬化表面上。 1.5 推荐的紧固件-- 符合中引用标准要求的紧固件 表3 被认为与列出的DTI等级或类别兼容。 1.6 英制DTI的规定值以英寸磅单位表示，公制DTI的值以国际单位表示。以国际单位制或英寸磅单位表示的数值应单独视为标准。每个系统中规定的值不一定是完全相等的； 因此，为了确保符合标准，每个系统应独立使用，并且两个系统的值不得组合。 1.7 以下预防声明仅适用于第节中的试验方法部分 12 本规范:本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.8 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。

1.1 This specification covers the requirements for carbon and alloy steel compressible-washer-type direct tension indicators (DTIs) capable of indicating a specified bolt tension in cap screws, bolts, anchors, and studs. 1.2 Direct tension indicators in inch sizes 1 / 4 through 2 1 / 2 in. and metric sizes M6 and M72 are covered. 1.3 Direct tension indicators have two styles and four grades for inch fasteners, Grades 5, 8, 55, and 105, and two property classes for metric fasteners, property classes 8.8 and 10.9 each of which differ in their compressive load requirements at a given gap (see Table 1 and Table 2 ). 1.3.1 Style 1 DTIs are suitable for comparatively smaller bearing surfaces. Style 1 DTIs are available in Grades 5 and 8, which differ in the amount of tension they indicate at a prescribed gap (see Table 1 and Table 3 ). 1.3.2 Style 2 DTIs are suitable for comparatively large bearing surfaces. Style 2 DTIs are available in Grades 55 and 105, which differ in the amount of tension they indicate at a prescribed gap (see Table 1 and Table 3 ). 1.4 Direct tension indicators are intended for installation under a bolt or cap screw head, a hex nut, or against a hardened washer or other flat hardened surface. 1.5 Recommended Fasteners— Fasteners meeting the requirements of the standards referenced in Table 3 are considered compatible with the DTI grade or class listed. 1.6 The values stated for Inch DTIs are expressed in inch-pound units and for Metric DTIs values are expressed in SI units. The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.7 The following precautionary statement pertains only to the test method portions, Section 12 of this specification: 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.8 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.