1.1 本规范涵盖了可压缩垫圈型直接张力指示器（DTI）的要求，DTI能够指示在结构螺栓组件中达到规定的最小张力。 1.2 标称直径尺寸的八种DTI 1. / 2. 到1 1. / 2. 在里面以及M16到M36: 1.2.1 325-1型- 用于规范的DTI F3125 等级 A325飞机 1型螺栓或等级 F1852 组件。 1.2.2 325-3型- 用于规范的DTI F3125 等级 A325飞机 3类螺栓或等级 F1852 类型3组件。 1.2.3 490-1型- 用于规范的DTI F3125 等级 A490 1型螺栓或等级 F2280页 组件。 1.2.4 490-3型- 用于规范的DTI F3125 等级 A490 3类螺栓等级 F2280页 类型3组件。 1.2.5 类型8.8-1- 用于规范的DTI F3125 等级 A325米 1型螺栓。 1.2.6 类型8.8-3- 用于规范的DTI F3125 等级 A325米 3类螺栓。 1.2.7 类型10.9-1- 用于规范的DTI F3125 等级 A490M 1型螺栓。 1.2.8 类型10.9-3- 用于规范的DTI F3125 等级 A490M 3类螺栓。 1.3 DTI用于安装，突出物紧靠硬化表面，如螺栓头、硬化螺母或硬化垫圈。 （见结构连接研究委员会:使用高强度螺栓的结构接头规范。） 1.4 本规范规定根据制造商的判断，按照化学成分要求或耐腐蚀指数（CRI）提供3类DTI。 1.5 本规范中使用的术语在术语中定义 F1789 除非另有规定。 1.6 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。 将两个系统的值合并可能会导致不符合标准。 1.7 以下预防说明仅适用于试验方法部分，第 10 和 附录X1 本规范: 本标准并非旨在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、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（TBT）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》中确立的国际公认标准化原则制定的。

1.1 This specification covers the requirements for compressible-washer-type direct tension indicators, (DTIs) capable of indicating the achievement of a specified minimum tension in a structural bolting assembly. 1.2 Eight types of DTIs in nominal diameter sizes 1 / 2 through 1 1 / 2 in. as well as M16 through M36 are covered: 1.2.1 Type 325-1— DTIs for use with Specification F3125 Grade A325 Type 1 bolts or Grade F1852 assemblies. 1.2.2 Type 325–3— DTIs for use with Specification F3125 Grade A325 Type 3 bolts or Grade F1852 Type 3 assemblies. 1.2.3 Type 490–1— DTIs for use with Specification F3125 Grade A490 Type 1 bolts or Grade F2280 assemblies. 1.2.4 Type 490–3— DTIs for use with Specification F3125 Grade A490 Type 3 bolts Grade F2280 Type 3 assemblies. 1.2.5 Type 8.8-1— DTIs for use with Specification F3125 Grade A325M Type 1 bolts. 1.2.6 Type 8.8-3— DTIs for use with Specification F3125 Grade A325M Type 3 bolts. 1.2.7 Type 10.9-1— DTIs for use with Specification F3125 Grade A490M Type 1 bolts. 1.2.8 Type 10.9-3— DTIs for use with Specification F3125 Grade A490M Type 3 bolts. 1.3 DTIs are intended for installation with the protrusions against a hardened surface such as a bolt head, a hardened nut, or a hardened washer. (See Research Council on Structural Connections: Specification for Structural Joints Using High–Strength Bolts.) 1.4 This specification provides for furnishing Type 3 DTIs to a Chemical Composition Requirement or a Corrosion Resistance Index (CRI) at the manufacturer’s discretion. 1.5 Terms used in this specification are defined in Terminology F1789 unless otherwise specified. 1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.7 The following precautionary statement pertains only to the test method portions, Section 10 and Appendix X1 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.