{"id":14593,"date":"2026-10-29T14:45:23","date_gmt":"2026-10-29T06:45:23","guid":{"rendered":"https:\/\/sunhyings.com\/?p=14593"},"modified":"2026-10-29T14:45:23","modified_gmt":"2026-10-29T06:45:23","slug":"astm-a325-vs-astm-a307-bolts-why-structural-and-general-purpose-grades-differ","status":"publish","type":"post","link":"https:\/\/sunhyings.com\/ar\/blog\/astm-a325-vs-astm-a307-bolts-why-structural-and-general-purpose-grades-differ\/","title":{"rendered":"\u0645\u0633\u0627\u0645\u064a\u0631 ASTM A325 \u0645\u0642\u0627\u0628\u0644 ASTM A307: \u0644\u0645\u0627\u0630\u0627 \u062a\u062e\u062a\u0644\u0641 \u062f\u0631\u062c\u0627\u062a \u0627\u0644\u0645\u0633\u0627\u0645\u064a\u0631 \u0627\u0644\u0625\u0646\u0634\u0627\u0626\u064a\u0629 \u0639\u0646 \u062f\u0631\u062c\u0627\u062a \u0627\u0644\u0623\u063a\u0631\u0627\u0636 \u0627\u0644\u0639\u0627\u0645\u0629"},"content":{"rendered":"\n<style>\n.sunhy-blog-article{max-width:100%;overflow-wrap:break-word;line-height:1.75}\n.sunhy-blog-article p{margin:0 0 1.1em}\n.sunhy-blog-article h2{margin:2em 0 .65em;line-height:1.3}\n.sunhy-blog-article h3{margin:1.55em 0 .55em;line-height:1.4}\n.sunhy-blog-article a{text-decoration:underline;text-underline-offset:2px}\n.sunhy-blog-article ul{padding-inline-start:1.45em;margin:0 0 1.2em}\n.sunhy-blog-article li{margin:.45em 0}\n.sunhy-blog-article .sunhy-table-wrap{max-width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch;margin:1.35em 0}\n.sunhy-blog-article .sunhy-table-wrap table{width:100%;min-width:640px;border-collapse:collapse;text-align:left}\n.sunhy-blog-article .sunhy-table-wrap th,.sunhy-blog-article .sunhy-table-wrap td{border:1px solid #d5dce4;padding:.7em .8em;vertical-align:top}\n.sunhy-blog-article .sunhy-table-wrap 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.sunhy-table-wrap td{padding:14px 16px;vertical-align:top;line-height:1.6;border-bottom:1px solid #dce5eb}.sunhy-blog-article .sunhy-table-wrap thead th{background:#183f5c;color:#fff;text-align:start;font-weight:700}.sunhy-blog-article .sunhy-table-wrap tbody tr:nth-child(even){background:#f3f7fa}.sunhy-blog-article .sunhy-table-wrap tbody tr:last-child td{border-bottom:0}.sunhy-blog-article blockquote{background:#f3f7fa;border-inline-start:4px solid #849fb3;margin:24px 0;padding:20px 24px}.sunhy-blog-article blockquote p:last-child{margin:0}.sunhy-blog-article .sunhy-equation{padding:18px 22px;background:#eef4f8;border:1px solid #d6e3ec;border-radius:8px}\n.sunhy-blog-article .sunhy-editorial-figure{margin:30px 0}.sunhy-blog-article .sunhy-editorial-figure img{display:block;width:100%;height:auto;aspect-ratio:3\/2;object-fit:contain;background:#eaf0f4;border-radius:10px}.sunhy-blog-article .sunhy-editorial-figure figcaption{font-size:13px;line-height:1.65;color:#617685;padding:11px 3px}.sunhy-blog-article .sunhy-related-reading{background:#f4f8fb}.sunhy-blog-article .sunhy-related-reading ul{margin:0}.sunhy-blog-article .sunhy-reference-box{border-top:1px solid #dce5eb;background:#f8fafb;padding:22px;margin:32px 0;border-radius:8px;font-size:14px}.sunhy-blog-article .sunhy-reference-box h2{font-size:22px;background:none;border:0;padding:0;margin-top:0}\n@media(max-width:767px){.sunhy-blog-article{font-size:16px;line-height:1.75}.sunhy-blog-article h2{font-size:23px;margin-top:32px;padding:10px 13px}.sunhy-blog-article h3{font-size:19px}.sunhy-blog-article .sunhy-toc ol{columns:1}.sunhy-blog-article .sunhy-summary-box,.sunhy-blog-article .sunhy-warning-box,.sunhy-blog-article .sunhy-procurement-note,.sunhy-blog-article .sunhy-related-reading,.sunhy-blog-article .sunhy-cta,.sunhy-blog-article .sunhy-toc{padding:19px}.sunhy-blog-article .sunhy-table-wrap th,.sunhy-blog-article .sunhy-table-wrap td{padding:11px 13px}}\n\n.sunhy-blog-article .sunhy-faq details{border:1px solid #d4e1eb;border-radius:8px;background:#f7fafc;padding:17px 20px;margin:12px 0}.sunhy-blog-article .sunhy-faq summary{cursor:pointer;font-weight:700;color:#183f5c;line-height:1.5}.sunhy-blog-article .sunhy-faq details p{margin:14px 0 0}.sunhy-blog-article .sunhy-faq summary:focus-visible{outline:3px solid #bc842d;outline-offset:4px}\n<\/style>\n<article class=\"sunhy-blog-article\">\n<aside class=\"sunhy-summary-box sunhy-added\" aria-label=\"Quick answer\"><p class=\"sunhy-box-label\">Quick answer<\/p><p>ASTM A307 and ASTM A325 bolts are not interchangeable grades of the same fastener. ASTM A307 covers carbon steel bolting for general and certain specified applications, while A325 is a high-strength structural bolt grade now covered by ASTM F3125\/F3125M. Their different mechanical requirements matter, but <strong>the governing connection design\u2014not tensile strength alone\u2014determines which bolt can be used<\/strong>.<\/p><\/aside><nav class=\"sunhy-toc sunhy-added\" aria-label=\"Article contents\"><p class=\"sunhy-toc-title\">In this guide<\/p><ol><li><a href=\"#astm-a307-and-a325-are-different-product-specifications\">ASTM A307 and A325 Are Different Product Specifications<\/a><\/li><li><a href=\"#why-strength-differences-change-structural-bolt-selection\">Why Strength Differences Change Structural Bolt Selection<\/a><\/li><li><a href=\"#when-a307-may-be-suitable-and-when-a325-must-be-retained\">When A307 May Be Suitable\u2014and When A325 Must Be Retained<\/a><\/li><li><a href=\"#head-geometry-threads-and-matching-hardware-also-matter\">Head Geometry, Threads and Matching Hardware Also Matter<\/a><\/li><li><a href=\"#what-to-verify-before-ordering-or-substituting-bolts\">What to Verify Before Ordering or Substituting Bolts<\/a><\/li><li><a href=\"#sunhy-faq-14593\">Frequently asked questions<\/a><\/li><\/ol><\/nav>\n<p>For comparison, ASTM A307 Grade A specifies a minimum tensile strength of 60 ksi, while ASTM F3125 Grade A325 belongs to the 120 ksi strength group. That difference does not mean an A325 connection automatically carries twice the load. Nor does it mean A307 bolts are prohibited from all structural applications. Certain engineered connections may use A307 where the applicable design requirements permit it.<\/p>\n<p>The practical question is whether the proposed bolt satisfies the connection&#8217;s specified strength, geometry, installation and inspection requirements. A bolt that fits the hole and accepts the nut has not necessarily met those conditions.<\/p>\n<h2 id=\"astm-a307-and-a325-are-different-product-specifications\">ASTM A307 and A325 Are Different Product Specifications<\/h2>\n<p>The first distinction is the governing ASTM product specification.<\/p>\n<p><a href=\"https:\/\/store.astm.org\/a0307-21.html\" target=\"_blank\" rel=\"noopener noreferrer nofollow\">ASTM A307-21<\/a> covers carbon steel bolts, studs and threaded rod within its defined scope. It distinguishes two grades relevant to different applications.<\/p>\n<p><strong>Grade A<\/strong> is commonly associated with general-purpose bolting and has a specified minimum tensile strength of 60 ksi. <strong>Grade B<\/strong> has a specified tensile strength range of 60\u2013100 ksi and is directed toward bolting for flanged joints in piping systems with cast iron flanges. Grade B is not simply an alternative designation for a high-strength structural bolt.<\/p>\n<p>A325 follows a different specification history. The former standalone ASTM A325 designation was incorporated into <a href=\"https:\/\/store.astm.org\/f3125_f3125m-26.html\" target=\"_blank\" rel=\"noopener noreferrer nofollow\">ASTM F3125\/F3125M<\/a>, which covers specified high-strength structural bolting products. Under that specification, Grade A325 identifies a high-strength heavy-hex structural bolt classification. ASTM F3125 also distinguishes types related to material chemistry and other product classifications.<\/p>\n<p>The A325 name remains common on structural drawings and purchasing documents. However, an RFQ should identify the governing F3125 specification and contractual edition rather than relying on the historical designation alone.<\/p>\n<div class=\"sunhy-table-wrap\" role=\"region\" aria-label=\"ASTM A307 and A325 specification comparison\" tabindex=\"0\">\n<table>\n<thead>\n<tr>\n<th>Specification and grade<\/th>\n<th>Specified tensile-strength basis<\/th>\n<th>Main application distinction<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>ASTM A307 Grade A<\/td>\n<td>60 ksi minimum<\/td>\n<td>General-purpose carbon steel bolting; possible structural use where permitted by design<\/td>\n<\/tr>\n<tr>\n<td>ASTM A307 Grade B<\/td>\n<td>60\u2013100 ksi specified range<\/td>\n<td>Bolting associated with cast iron flanged piping joints<\/td>\n<\/tr>\n<tr>\n<td>ASTM F3125 Grade A325<\/td>\n<td>Group 120; 120 ksi minimum<\/td>\n<td>High-strength structural bolting for connections meeting applicable design and installation requirements<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>These are product material-strength requirements, not allowable connection loads. The values are taken from the identified ASTM product specification information and the RCSC 2025 classification of Group 120 bolts. Detailed acceptance conditions still depend on the applicable edition, product dimensions and test requirements.<\/p>\n<p>This distinction matters when a purchase order says only &quot;A307 bolts&quot; or &quot;A325 bolts.&quot; Such descriptions may not fully identify the grade, material type, dimensions, finish or acceptance documents required for a particular job.<\/p>\n<h2 id=\"why-strength-differences-change-structural-bolt-selection\">Why Strength Differences Change Structural Bolt Selection<\/h2>\n<p>The higher specified tensile strength of A325 is important because it gives the designer a different material-strength basis. But the strength of a structural connection depends on more than the steel used to make the bolt.<\/p>\n<h3>Bolt tensile strength is not connection design strength<\/h3>\n<p>Tensile strength describes the material&#8217;s resistance to fracture under tensile loading. When a bolt carries tension, the effective resisting area also matters. The threaded portion does not have the same effective tensile area as a solid shank of the same nominal diameter.<\/p>\n<p>In shear, the position of the shear plane relative to the threads can affect the bolt&#8217;s calculated resistance. A connection with a shear plane through the threads may have a different design basis from one where the plane passes through the unthreaded shank.<\/p>\n<p>Other parts of the connection can govern before the bolt reaches its material strength limit. Depending on the configuration, the designer may need to evaluate bolt shear or tension, combined loading, connected-material bearing, edge distance, hole geometry, tear-out or other applicable limit states.<\/p>\n<aside class=\"sunhy-warning-box sunhy-added\" aria-label=\"Important specification check\"><p class=\"sunhy-box-label\">Important specification check<\/p><p>Consider two bolt grades with specified minimum tensile strengths of 60 ksi and 120 ksi. Their nominal material tensile-strength values differ by a factor of two. Yet that comparison does not establish a twofold difference in design resistance because the bolt geometry, applicable strength factors, loading and governing failure mode have not been established.<\/p><\/aside>\n<p>For that reason, replacing a specified A325 bolt with A307 requires more than checking whether the anticipated load seems smaller than the published tensile-strength figure.<\/p>\n<h3>Pretension and slip resistance are separate requirements<\/h3>\n<p>Another source of confusion is the difference between bolt strength and bolt pretension.<\/p>\n<p>Pretension is the tensile force intentionally developed in a bolt during installation. It helps clamp the connected parts together. The required pretension, where applicable, is an installation and connection-design requirement; it is not another name for the material&#8217;s minimum tensile strength.<\/p>\n<p>The <a href=\"https:\/\/www.boltcouncil.org\/files\/2025RCSCSpecification.pdf\" target=\"_blank\" rel=\"noopener noreferrer nofollow\">RCSC 2025 Specification for Structural Joints Using High-Strength Bolts<\/a> distinguishes snug-tightened, pretensioned and slip-critical connections.<\/p>\n<p>In an appropriately designed snug-tightened bearing-type connection, load transfer may be evaluated through bolt shear and bearing of the connected materials without relying on a specified installation pretension for slip resistance.<\/p>\n<p>A pretensioned connection requires a defined installation condition. A slip-critical connection adds resistance to slip at the faying surfaces as a design consideration, making the specified clamping force and contact-surface condition important.<\/p>\n<p>These distinctions mean that merely installing a stronger bolt does not automatically create a compliant pretensioned or slip-critical connection. Conversely, the fact that a connection is snug-tightened does not prove that a lower-strength bolt is adequate for its design loads.<\/p>\n<p>A325 bolts may be used in connections designed for snug-tightened installation as well as in connections requiring pretension, subject to the governing requirements. The connection category and specified bolt grade must therefore be evaluated separately.<\/p>\n<figure class=\"sunhy-editorial-figure sunhy-added\"><img loading=\"lazy\" src=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2026\/10\/heavy-hex-vs-standard-hex-heads-sunhy.webp\" alt=\"Heavy hex and standard hex bolt heads compared on an inspection bench\" width=\"1536\" height=\"1024\" loading=\"lazy\" decoding=\"async\" class=\"wp-image-14629\" title=\"A325 vs a307 structural bolts \u2014 illustrative inspection view\" srcset=\"https:\/\/sunhyings.com\/wp-content\/uploads\/2026\/10\/heavy-hex-vs-standard-hex-heads-sunhy.webp 1536w, https:\/\/sunhyings.com\/wp-content\/uploads\/2026\/10\/heavy-hex-vs-standard-hex-heads-sunhy-800x533.webp 800w, https:\/\/sunhyings.com\/wp-content\/uploads\/2026\/10\/heavy-hex-vs-standard-hex-heads-sunhy-1024x683.webp 1024w, https:\/\/sunhyings.com\/wp-content\/uploads\/2026\/10\/heavy-hex-vs-standard-hex-heads-sunhy-768x512.webp 768w, https:\/\/sunhyings.com\/wp-content\/uploads\/2026\/10\/heavy-hex-vs-standard-hex-heads-sunhy-18x12.webp 18w\" sizes=\"auto, (max-width: 1536px) 100vw, 1536px\" \/><figcaption>Heavy hex and standard hex bolt heads compared on an inspection bench. Illustrative arrangement; appearance does not establish grade or product conformity.<\/figcaption><\/figure><h2 id=\"when-a307-may-be-suitable-and-when-a325-must-be-retained\">When A307 May Be Suitable\u2014and When A325 Must Be Retained<\/h2>\n<p>It would be incorrect to say that every structural connection requires A325 bolts.<\/p>\n<p>The <a href=\"https:\/\/www.aisc.org\/aisc\/publications\/current-standards\/aisc-360\/\" target=\"_blank\" rel=\"noopener noreferrer nofollow\">AISC 360-22 structural steel specification<\/a> recognizes the use of common bolts, including ASTM A307, within its applicable design provisions. Such use depends on the connection satisfying its engineering requirements. It does not establish permission to use A307 wherever a structural drawing calls for a bolt.<\/p>\n<p>The distinction becomes clearer when considering three situations.<\/p>\n<p><strong>An engineered connection permits common bolts.<\/strong> If the applicable design allows A307, the intended grade and dimensions are specified, and the connection is not required to develop a defined high-strength bolt pretension, A307 may be an appropriate selection. Its adequacy still depends on the actual loading and connection geometry.<\/p>\n<p><strong>The drawing specifies A325 but the connection is snug-tightened.<\/strong> The absence of a pretension requirement is not permission to substitute A307. The designer may have selected A325 because the connection needs the strength associated with that grade. The proposed substitution must be checked against the original design requirements.<\/p>\n<p><strong>The connection requires pretensioned or slip-critical high-strength bolting.<\/strong> A307 should not be treated as a direct substitute for the specified A325 assembly. The governing requirements include the qualified fastener components and installation or inspection conditions, not just the physical dimensions of a bolt.<\/p>\n<p>These are different engineering situations, even if the bolts have the same nominal diameter.<\/p>\n<h3>Hypothetical procurement example<\/h3>\n<p>Suppose a structural drawing specifies 3\/4-inch ASTM F3125 Grade A325 heavy-hex bolts for a pretensioned connection. A supplier offers 3\/4-inch ASTM A307 Grade A bolts of the same nominal length.<\/p>\n<p>The two items might appear similar on a quotation. They are not equivalent to the specified purchase requirement.<\/p>\n<p>First, A307 Grade A and F3125 Grade A325 have different mechanical requirements. Second, the drawing requires a pretensioned connection using the specified structural bolting system. Third, nominal size and length alone do not confirm the same head geometry, threaded length or matching hardware requirements.<\/p>\n<p>The procurement team should not approve the change on price, availability or nominal dimensions alone. The proposed substitution must be referred to the party authorized to approve the connection design, with the replacement product&#8217;s actual specifications and supporting documents available for review.<\/p>\n<p>If the proposed grade cannot satisfy the governing requirements, it must not be accepted as a direct replacement. If a redesign is considered, its acceptance requires an appropriate engineering basis rather than a supplier&#8217;s statement that the replacement bolt will fit.<\/p>\n<p>This is an illustrative purchasing scenario, not a reported SUNHY customer project or field failure.<\/p>\n<p>The same caution applies in the opposite direction. Replacing A307 with A325 solely because A325 has a higher tensile-strength classification does not automatically establish compliance with the original drawing, installation conditions or connected-component requirements.<\/p>\n<p class=\"sunhy-engineering-example sunhy-added\" data-example=\"1\">In a hypothetical handrail repair, a buyer offers an A307 bolt because it fits the same hole as the specified A325. The unresolved issue is the connection design, not the hole fit. Return the proposal with the actual grade, geometry and installation condition to the responsible engineer. Release a substitute only after the governing requirements have been reconciled.<\/p>\n\n<h2 id=\"head-geometry-threads-and-matching-hardware-also-matter\">Head Geometry, Threads and Matching Hardware Also Matter<\/h2>\n<p>Mechanical grade is only one part of a complete bolt specification.<\/p>\n<p>ASTM F3125 Grade A325 heavy-hex bolts follow a structural fastener product and dimensional system. <a href=\"https:\/\/www.asme.org\/codes-standards\/find-codes-standards\/b18-2-6-fasteners-use-structural-applications-supplement\/2019\/pdf\" target=\"_blank\" rel=\"noopener noreferrer nofollow\">ASME B18.2.6<\/a> addresses dimensional requirements for fasteners used in structural applications, while other hex-head product forms may fall under different dimensional standards.<\/p>\n<p>A307 fasteners are not all automatically identical in head style or configuration. Their actual product form must be identified from the applicable specification, drawing and order.<\/p>\n<p>The distinction has practical consequences at the connection.<\/p>\n<p><strong>Head geometry and bearing surfaces.<\/strong> A heavy-hex head and a standard hex head may have different wrenching dimensions and bearing arrangements. Available installation clearance, mating surfaces and specified washer arrangements must be checked rather than assumed to be interchangeable.<\/p>\n<p><strong>Thread length and grip.<\/strong> Overall bolt length alone does not establish where the threaded portion will fall after installation. The grip includes the connected material thicknesses, and the actual assembly may also include washers. Thread position can affect the connection&#8217;s design evaluation when a shear plane passes through the threaded portion rather than the unthreaded shank.<\/p>\n<p><strong>Matching nuts and washers.<\/strong> The correct nut grade, type, dimensions and finish depend on the bolt specification and applicable assembly requirements. High-strength structural bolting may require particular combinations of nuts and hardened washers under defined conditions. An ordinary nut or washer should not be accepted merely because its nominal thread size matches the bolt.<\/p>\n<p><strong>Coating and installation compatibility.<\/strong> Coatings can affect thread fit and fastening behavior. For structural bolting assemblies, applicable coating, lubrication, component compatibility and verification requirements must be considered together. A coating permitted for one configuration cannot automatically be assumed acceptable for every grade, type or assembly.<\/p>\n<p>An A325 designation therefore identifies a product classification, not proof that any nut, washer and coating combination constitutes an acceptable structural bolting assembly.<\/p>\n<p>This is particularly relevant when a supplier quotes an individual bolt rather than a complete, specified bolting assembly. The additional components may affect both compliance and what must be inspected at delivery.<\/p>\n<p class=\"sunhy-engineering-example sunhy-added\" data-example=\"2\">An illustrative receiving check finds that the delivered bolt diameter matches, but the head cannot accept the scheduled structural-bolting socket and the nut style differs. Selecting by diameter alone caused the mismatch. Verify <a href=\"https:\/\/sunhyings.com\/blog\/how-to-measure-hex-bolt-dimensions\/\">bolt length, diameter and pitch<\/a>, then check the governing head dimensions and compatible components before returning or releasing the delivery.<\/p>\n\n<h2 id=\"what-to-verify-before-ordering-or-substituting-bolts\">What to Verify Before Ordering or Substituting Bolts<\/h2>\n<p>A purchasing specification should allow the supplier and receiving inspector to identify the same product that the engineer has approved.<\/p>\n<p>For an A307 or A325 order, the important information is not just the nominal diameter and quantity. The RFQ should address:<\/p>\n<ul>\n<li><strong>Governing specification and edition:<\/strong> ASTM A307 Grade A or B, or ASTM F3125\/F3125M Grade A325 with the required type and product classification. Record the edition required by the contract.<\/li>\n<li><strong>Physical configuration:<\/strong> Nominal diameter, length, thread designation, head form and applicable dimensional standard. Include a drawing where thread position, grip or assembly clearance is important.<\/li>\n<li><strong>Connection requirements:<\/strong> Identify whether the application is an engineered common-bolt connection or one requiring specified high-strength structural bolting, pretension or slip-critical performance. The design authority should define these requirements.<\/li>\n<li><strong>Matching components and finish:<\/strong> Specify the compatible nut and washer requirements, coating or other surface treatment, and any assembly-related conditions required by the governing project.<\/li>\n<li><strong>Inspection and traceability:<\/strong> State what manufacturer identification, lot or heat traceability, certificates of conformity, material or mechanical test records, dimensional inspection and other documents are required for acceptance.<\/li>\n<li><strong>Substitution approval:<\/strong> If the proposed product differs from the drawing or purchase specification, obtain the appropriate engineering disposition before authorizing the change.<\/li>\n<\/ul>\n<p>The documentation itself also needs careful interpretation.<\/p>\n<p>A bolt-head marking helps identify the product classification and manufacturer. It does not independently demonstrate that every applicable mechanical, chemical or dimensional requirement has been met for the delivered lot.<\/p>\n<p>A certificate of conformity communicates a claim of compliance within its stated scope. A material or mechanical test record provides reported results for identified material, samples or product lots, as applicable. The buyer must determine which records the contract requires and whether the supplied records can be traced to the delivered items.<\/p>\n<p>ASTM F606\/F606M describes mechanical testing methods for threaded fasteners, but the existence of that test-method standard does not mean every A307 or A325 bolt is subjected to every available method. The applicable product specification, edition and order requirements determine the relevant acceptance basis.<\/p>\n<p>For high-strength structural bolting, product acceptance and installed-joint verification are distinct responsibilities. A bolt that meets its ASTM product requirements has not automatically been demonstrated to be installed in compliance with the applicable RCSC requirements.<\/p>\n<h3>The decision to put on the purchase order<\/h3>\n<p>When a drawing specifies ASTM F3125 Grade A325, the purchasing team should quote and order against that specification unless an authorized engineering change has been approved.<\/p>\n<p>When an engineered design permits ASTM A307, the RFQ should state the correct A307 grade and all relevant dimensions and acceptance requirements. There is no technical benefit in automatically upgrading the material designation without confirming its effect on the specified assembly.<\/p>\n<p>In both cases, procurement needs a clearly identified product, a verified design basis and documentary evidence appropriate to the order.<\/p>\n<aside class=\"sunhy-procurement-note sunhy-added\"><p>For a <a href=\"https:\/\/sunhyings.com\/fasteners\/bolts\/structural-bolts\/\">structural bolt RFQ<\/a> involving SUNHY, provide the approved bolt specification, drawing, required finish, matching components and inspection documents through the <a href=\"https:\/\/sunhyings.com\/contact-us\/\">contact page<\/a>. Availability, exact configurations and applicable quality records must be confirmed for the specific order.<\/p><\/aside>\n<aside class=\"sunhy-related-reading sunhy-added\" aria-label=\"Related technical reading\"><p class=\"sunhy-box-label\">Related technical reading<\/p><ul><li><a href=\"https:\/\/sunhyings.com\/fasteners\/bolts\/structural-bolts\/\">Structural bolt specification and enquiry<\/a><\/li><li><a href=\"https:\/\/sunhyings.com\/blog\/hex-nut-grades-explained\/\">Hex nut grades and selection checks<\/a><\/li><li><a href=\"https:\/\/sunhyings.com\/blog\/understanding-bolt-grades\/\">Bolt grades and strength terminology<\/a><\/li><li><a href=\"https:\/\/sunhyings.com\/blog\/traceability-for-automotive-fasteners\/\">Fastener lot control and inspection-record principles<\/a><\/li><\/ul><\/aside>\n<section class=\"sunhy-faq sunhy-added\" aria-labelledby=\"sunhy-faq-14593\"><h2 id=\"sunhy-faq-14593\">Frequently asked questions<\/h2><details><summary>Is A325 stronger than A307?<\/summary><p>They have different mechanical requirements, but a strength comparison alone does not approve a connection. Use the specified grade and design basis.<\/p><\/details><details><summary>Can A307 replace A325 when the diameter is the same?<\/summary><p>Not as an automatic substitution. Geometry, strength, assembly and installation requirements must all be checked and the required engineering approval obtained.<\/p><\/details><details><summary>Does tightening A307 harder make it equivalent to A325?<\/summary><p>No. Extra torque does not change the product grade and may damage the fastener or joint. Follow the approved product and installation requirements.<\/p><\/details><\/section>\n<\/article>\n<script type=\"application\/ld+json\">{\"@context\": \"https:\/\/schema.org\", \"@type\": \"FAQPage\", \"@id\": \"https:\/\/sunhyings.com\/blog\/astm-a325-vs-astm-a307-bolts-why-structural-and-general-purpose-grades-differ\/#faq\", \"mainEntity\": [{\"@type\": \"Question\", \"name\": \"Is A325 stronger than A307?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"They have different mechanical requirements, but a strength comparison alone does not approve a connection. Use the specified grade and design basis.\"}}, {\"@type\": \"Question\", \"name\": \"Can A307 replace A325 when the diameter is the same?\", \"acceptedAnswer\": {\"@type\": \"Answer\", \"text\": \"Not as an automatic substitution. 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Follow the approved product and installation requirements.\"}}]}<\/script>\n\n","protected":false},"excerpt":{"rendered":"<p>\u0642\u0627\u0631\u0646 \u0628\u064a\u0646 \u062f\u0631\u062c\u062a\u064a \u0627\u0644\u0645\u0633\u0627\u0645\u064a\u0631 ASTM A325 \u0648A307 \u0648\u0627\u0644\u062a\u0637\u0628\u064a\u0642\u0627\u062a \u0627\u0644\u0625\u0646\u0634\u0627\u0626\u064a\u0629 \u0648\u0645\u062a\u0637\u0644\u0628\u0627\u062a \u0627\u0644\u0634\u062f \u0627\u0644\u0645\u0633\u0628\u0642. \u062a\u0639\u0631\u0651\u0641 \u0639\u0644\u0649 \u0633\u0628\u0628 \u0639\u062f\u0645 \u062a\u0628\u0631\u064a\u0631 \u0627\u0644\u0623\u062d\u062c\u0627\u0645 \u0627\u0644\u0645\u062a\u0633\u0627\u0648\u064a\u0629 \u0644\u0644\u0627\u0633\u062a\u0628\u062f\u0627\u0644 \u0627\u0644\u0645\u0628\u0627\u0634\u0631.<\/p>","protected":false},"author":1,"featured_media":14624,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-14593","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-selection-comparison"],"_links":{"self":[{"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/posts\/14593","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/comments?post=14593"}],"version-history":[{"count":3,"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/posts\/14593\/revisions"}],"predecessor-version":[{"id":14691,"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/posts\/14593\/revisions\/14691"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/media\/14624"}],"wp:attachment":[{"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/media?parent=14593"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/categories?post=14593"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sunhyings.com\/ar\/wp-json\/wp\/v2\/tags?post=14593"}],"curies":[{"name":"\u062f\u0628\u0644\u064a\u0648 \u0628\u064a","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}