{"id":69614,"date":"2026-05-17T17:27:13","date_gmt":"2026-05-17T17:27:13","guid":{"rendered":"https:\/\/evgroupchina.com\/encyclopedia-of-metal\/astm-f959-m-asme-sf959-m\/"},"modified":"2026-05-19T15:29:56","modified_gmt":"2026-05-19T15:29:56","slug":"astm-f959-m-asme-sf959-m","status":"publish","type":"wiki","link":"https:\/\/evgroupchina.com\/en\/encyclopedia-of-metal\/astm-f959-m-asme-sf959-m\/","title":{"rendered":"ASTM F959 M \/ ASME SF959 M"},"content":{"rendered":"<h2>Technical Regulation and Scope of Application for ASTM F959 \/ F959M Indicators<\/h2>\n<p>This specification establishes strict engineering requirements for compressible-washer-type Direct Tension Indicators (DTI). These elements are used in critical structural construction for visual and instrumental verification of achieving the specified pretension force in bolted connections.<\/p>\n<p>The standard classifies eight types of DTIs, covering a wide range of nominal diameters\u2014from 1\/2 to 1 1\/2 inches, as well as metric sizes from M16 to M36:<\/p>\n<ul>\n<li>Type 325-1: intended for installation with F3125 standard bolts (Grade A325, Type 1) or F1852 assemblies.<\/li>\n<li>Type 325-3: for use with F3125 bolts (Grade A325, Type 3) or F1852, Type 3 assemblies.<\/li>\n<li>Type 490-1: for high-strength F3125 bolts (Grade A490, Type 1) or F2280 assemblies.<\/li>\n<li>Type 490-3: for F3125 bolts (Grade A490, Type 3) and F2280 Type 3 connections.<\/li>\n<li>Type 8.8-1: compatible with metric F3125 bolts of Grade A325M (Type 1).<\/li>\n<li>Type 8.8-3: for operation with F3125 bolts of Grade A325M (Type 3).<\/li>\n<li>Type 10.9-1: for high-strength metric F3125 bolts of Grade A490M (Type 1).<\/li>\n<li>Type 10.9-3: for F3125 bolts of Grade A490M (Type 3).<\/li>\n<\/ul>\n<p>EV Group China indicators are installed such that the DTI protrusions face a hardened surface\u2014the bolt head, a hardened nut, or a washer. Application of these products must strictly comply with the current recommendations of the Research Council on Structural Connections (RCSC).<\/p>\n<p>EV Group China manufacturing standards provide for the production of Type 3 washers taking into account chemical composition requirements or Corrosion Resistance Index (CRI), which guarantees the durability of connections in aggressive environments.<\/p>\n<p>Technical terms used within this standard correspond to the F1789 nomenclature. When designing assemblies, it should be noted that SI and inch-pound units are independent systems; attempting to combine them may lead to a violation of tension tolerances and a reduction in the load-bearing capacity of the assembly.<\/p>\n<p>All EV Group China products undergo verification testing according to Section 10 and Annex X1. This standard is based on the international principles of developing technical regulations of the WTO Committee on Technical Barriers to Trade (TBT).<\/p>\n","protected":false},"featured_media":0,"template":"","meta":[],"wiki_category":[112],"class_list":["post-69614","wiki","type-wiki","status-publish","hentry","wiki_category-astm"],"_links":{"self":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki\/69614","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/types\/wiki"}],"version-history":[{"count":0,"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki\/69614\/revisions"}],"wp:attachment":[{"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/media?parent=69614"}],"wp:term":[{"taxonomy":"wiki_category","embeddable":true,"href":"https:\/\/evgroupchina.com\/en\/wp-json\/wp\/v2\/wiki_category?post=69614"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}