{"id":100040,"date":"2026-02-15T20:07:51","date_gmt":"2026-02-15T20:07:51","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100040"},"modified":"2026-07-11T21:25:59","modified_gmt":"2026-07-11T21:25:59","slug":"bolt-preload-calculator","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/bg\/calculators\/bolt-preload-calculator\/","title":{"rendered":"Bolt Axial Reference-Load Fraction Calculator"},"content":{"rendered":"\r\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Bolt Axial Reference-Load Fraction Calculator\",\"description\":\"Multiply a user-supplied tensile stress area by a user-supplied reference stress and selected fraction. This is not a bolted-joint preload or tightening-torque design.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/bolt-preload-calculator\/\",\"applicationCategory\":\"Engineering Calculator\",\"operatingSystem\":\"Any\",\"offers\":{\"@type\":\"Offer\",\"price\":\"0\",\"priceCurrency\":\"EUR\"},\"creator\":{\"@type\":\"Organization\",\"name\":\"Vibromera\",\"url\":\"https:\/\/vibromera.eu\/\"},\"dateModified\":\"2026-07-11\",\"inLanguage\":\"en\",\"isAccessibleForFree\":true}<\/script>\r\n\r\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"Does ISO 898-1 specify tightening preload or torque?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. ISO 898-1:2013 specifies mechanical and physical fastener properties and explicitly excludes torque\/clamp-force performance. This page only multiplies user-supplied stress area, reference stress and fraction.\"}},{\"@type\":\"Question\",\"name\":\"Can the result be used as a joint preload target?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Not by itself. A joint target requires load, stiffness, separation, fatigue, embedment, temperature, thread and bearing limits, tightening scatter and verification of the assembly method.\"}},{\"@type\":\"Question\",\"name\":\"Why was the torque output removed?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"A generic nut-factor preset cannot represent the actual friction distributions, geometry, coating, lubrication and assembly process. Torque\/clamp behaviour should be established from qualified procedure or testing such as ISO 16047.\"}}]}<\/script>\r\n\r\n<script type=\"application\/ld+json\">\r\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"BreadcrumbList\",\"itemListElement\":[\r\n{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/vibromera.eu\/\"},\r\n{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Calculators\",\"item\":\"https:\/\/vibromera.eu\/calculators\/\"},\r\n{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Bolt Preload Calculator\",\"item\":\"https:\/\/vibromera.eu\/calculators\/bolt-preload-calculator\/\"}\r\n]}\r\n<\/script>\r\n\r\n<link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\">\r\n\r\n<link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin>\r\n\r\n<link 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20px;font-size:13px;font-weight:700;color:#fff;background:var(--vc-accent);border-radius:var(--vc-radius);text-decoration:none;white-space:nowrap;transition:background 0.15s;}\r\n.vc-promo-link:hover{background:var(--vc-accent-hover);}\r\n.vc-footer{text-align:center;padding:32px 16px;font-size:13px;color:var(--vc-ink-muted);}\r\n.vc-footer a{color:var(--vc-accent);text-decoration:none;}.vc-footer a:hover{text-decoration:underline;}\r\n.vc-footer-links{margin-top:8px;font-size:12px;}.vc-footer-links a{margin:0 8px;}\r\n@media print{.vc-section-body{max-height:none!important;}.vc-faq-a{max-height:none!important;}.vc-results{max-height:none!important;padding:24px!important;}.vc-copy-btn,.vc-section-chevron,.vc-faq-chevron,.vc-presets,.vc-promo{display:none!important;}}\r\n<\/style>\r\n\r\n<div class=\"vc-calculator\" id=\"vc-bolt-preload\">\r\n\r\n<header class=\"vc-header\"><p class=\"vc-header-eyebrow\">Scoped Engineering Calculation<\/p><h1 class=\"vc-header-title\">Bolt Axial Reference-Load Fraction<\/h1><p class=\"vc-header-subtitle\">Calculate F = \u03b7\u00b7\u03c3ref\u00b7As from three user-supplied values. This is a stress-area multiplication, not an automatic joint-preload or tightening-torque design.<\/p><div class=\"vc-badges\"><span class=\"vc-badge\">User-Supplied Data<\/span><span class=\"vc-badge\">No Generic Torque<\/span><span class=\"vc-badge\">Not \u201cPreload per ISO\u201d<\/span><\/div><\/header>\r\n\r\n<div class=\"vc-card\"><form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\"><div class=\"vc-form-grid\"><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-area\">Tensile stress area A<sub>s<\/sub> <span class=\"vc-label-hint\">(mm\u00b2; from exact thread\/source)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-area\" inputmode=\"decimal\" value=\"58\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-stress\">Reference axial stress \u03c3<sub>ref<\/sub> <span class=\"vc-label-hint\">(MPa = N\/mm\u00b2)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-stress\" inputmode=\"decimal\" value=\"640\"><\/div><div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-fraction\">Selected fraction \u03b7 <span class=\"vc-label-hint\">(%, user-defined)<\/span><\/label><input class=\"vc-input\" type=\"text\" id=\"vc-fraction\" inputmode=\"decimal\" value=\"70\"><\/div><\/div><div class=\"vc-warning-box\"><p style=\"margin:0\"><strong>Do not select \u03b7 here by rule of thumb.<\/strong> Enter a value established by the joint design and qualified assembly procedure. Check combined tension\/torsion, tightening scatter, external load, separation, fatigue, embedment, relaxation, temperature, mating threads, bearing surfaces and clamped-part limits.<\/p><\/div><\/form><div class=\"vc-results\" id=\"vc-results\"><div class=\"vc-results-head\"><h2 class=\"vc-results-title\">Arithmetic result<\/h2><button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\">Copy<\/button><\/div><div class=\"vc-result-grid\"><div class=\"vc-rcard vc-rcard-primary\"><div class=\"vc-rcard-label\">Selected axial load \u03b7\u00b7\u03c3ref\u00b7As<\/div><div class=\"vc-rcard-value\" id=\"vc-r-load\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Reference-area load \u03c3ref\u00b7As<\/div><div class=\"vc-rcard-value\" id=\"vc-r-reference\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Selected axial stress \u03b7\u00b7\u03c3ref<\/div><div class=\"vc-rcard-value\" id=\"vc-r-applied-stress\">\u2014<\/div><\/div><div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Input fraction<\/div><div class=\"vc-rcard-value\" id=\"vc-r-fraction\">\u2014<\/div><\/div><\/div><\/div><\/div>\r\n\r\n<div class=\"vc-section vc-open\" id=\"vc-sec-theory\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udcd8<\/span><span class=\"vc-section-title\">Equation and strict applicability boundary<\/span><\/span><\/button><div class=\"vc-section-body\"><div class=\"vc-section-inner vc-theory\"><h3>Arithmetic model<\/h3><div class=\"vc-formula-box\">F<sub>ref<\/sub> = \u03c3<sub>ref<\/sub>A<sub>s<\/sub>; &nbsp; F = \u03b7F<sub>ref<\/sub><\/div><p>Because 1 MPa = 1 N\/mm\u00b2, stress times stress area gives newtons. The page does not decide whether \u03c3ref should be proof stress, lower yield strength, 0.2% proof strength or a lower design value; use the exact value applicable to the fastener, diameter, temperature and governing procedure.<\/p><h3>What ISO 898-1 actually covers<\/h3><p><a href=\"https:\/\/www.iso.org\/standard\/60610.html\" target=\"_blank\" rel=\"noopener\">ISO 898-1:2013<\/a>, confirmed in 2025 and currently marked for revision, specifies mechanical and physical properties of carbon\/alloy-steel bolts, screws and studs at 10\u201335 \u00b0C. Its stated metric-thread scope is M1.6\u2013M39, and it explicitly does <strong>not<\/strong> specify torque\/clamp-force performance, fatigue resistance or shear resistance.<\/p><h3>Joint design and assembly<\/h3><p><a href=\"https:\/\/www.vdi.de\/en\/home\/vdi-standards\/details\/vdi-2230-blatt-1-systematische-berechnung-hochbeanspruchter-schraubenverbindungen-zylindrische-einschraubenverbindungen\" target=\"_blank\" rel=\"noopener\">VDI 2230 Part 1:2015<\/a> covers systematic joint calculation, including minimum clamp load, preload changes, assembly preload, tightening torque and strength verification. This three-input page does not claim VDI conformity. <a href=\"https:\/\/www.iso.org\/standard\/27788.html\" target=\"_blank\" rel=\"noopener\">ISO 16047:2005+Amd1:2012<\/a> specifies torque\/clamp-force test conditions; it is not replaced by a universal K preset.<\/p><div class=\"vc-info-box\"><p><strong>Source responsibility:<\/strong> obtain As and \u03c3ref from the current licensed product\/thread standard, verified manufacturer data or material certificate. For stainless, elevated\/low temperature, reduced-head geometry or sizes outside scope, use the applicable source rather than ISO 898-1 values.<\/p><\/div><\/div><\/div><\/div>\r\n\r\n<div class=\"vc-section\" id=\"vc-sec-related\">\r\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\">\r\n        <span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\ud83d\udd17<\/span><span class=\"vc-section-title\">Related Calculators<\/span><\/span>\r\n        <svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg>\r\n    <\/button>\r\n    <div class=\"vc-section-body\">\r\n        <div class=\"vc-section-inner\">\r\n            <div class=\"vc-related\">\r\n                <a class=\"vc-related-link\" href=\"\/calculators\/bolt-strength-calculator\/\">Bolt Strength Calculator<\/a>\r\n                <a class=\"vc-related-link\" href=\"\/calculators\/flange-bolt-calculator\/\">Flange Bolt Calculator<\/a>\r\n                <a class=\"vc-related-link\" href=\"\/calculators\/stud-bolt-torque\/\">Stud Bolt Torque<\/a>\r\n                <a class=\"vc-related-link\" href=\"\/calculators\/hydraulic-wrench-torque\/\">Hydraulic Wrench Torque<\/a>\r\n            <\/div>\r\n        <\/div>\r\n    <\/div>\r\n<\/div>\r\n\r\n<div class=\"vc-section\" id=\"vc-sec-faq\">\r\n    <button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\">\r\n        <span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">\u2753<\/span><span class=\"vc-section-title\">Frequently Asked Questions<\/span><\/span>\r\n        <svg class=\"vc-section-chevron\" viewBox=\"0 0 24 24\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\"><path d=\"M6 9l6 6 6-6\"\/><\/svg>\r\n    <\/button>\r\n    <div class=\"vc-section-body\">\r\n        <div class=\"vc-section-inner\">\r\n            <div class=\"vc-faq-list\" id=\"vc-faq-list\"><\/div>\r\n        <\/div>\r\n    <\/div>\r\n<\/div>\r\n\r\n<div class=\"vc-promo\">\r\n    <div class=\"vc-promo-text\"><strong>Vibromera \u2014 Portable Balancing &amp; Vibration Analysis<\/strong><br>Professional field balancing instruments and software. Used in 50+ countries.<\/div>\r\n    <a class=\"vc-promo-link\" href=\"https:\/\/vibromera.eu\/\" target=\"_blank\" rel=\"noopener\">Learn More<\/a>\r\n<\/div>\r\n\r\n<footer class=\"vc-footer\"><p>\u00a9 2024\u20132026 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a> \u2014 Engineering Calculators<\/p><p style=\"font-size:12px;margin-top:4px\">User-data stress-area arithmetic only; not an ISO\/VDI joint design or torque recommendation. Scientific review: July 2026.<\/p><\/footer>\r\n<\/div>\r\n\r\n<script>(function(){'use strict';function $(id){return document.getElementById(id)}function parsePositive(raw){var s=String(raw).trim().replace(\/\\s+\/g,'');if(!\/^[+]?(?:\\d+(?:[.,]\\d*)?|[.,]\\d+)$\/.test(s))return NaN;var n=Number(s.replace(',','.'));return Number.isFinite(n)&&n>0?n:NaN}function fmt(n,d){return Number.isFinite(n)?n.toFixed(d).replace(\/(\\.\\d*?)0+$\/,'$1').replace(\/\\.$\/,''):'\u2014'}function calculate(){var As=parsePositive($('vc-area').value),stress=parsePositive($('vc-stress').value),pct=parsePositive($('vc-fraction').value);if(![As,stress,pct].every(Number.isFinite)||pct>100){$('vc-results').classList.remove('vc-visible');return}var eta=pct\/100,ref=stress*As,load=eta*ref,applied=eta*stress;if(![ref,load,applied].every(Number.isFinite)){$('vc-results').classList.remove('vc-visible');return}$('vc-r-load').innerHTML=fmt(load\/1000,6)+' <span class=\"vc-rcard-unit\">kN ('+fmt(load,3)+' N)<\/span>';$('vc-r-reference').innerHTML=fmt(ref\/1000,6)+' <span class=\"vc-rcard-unit\">kN<\/span>';$('vc-r-applied-stress').innerHTML=fmt(applied,6)+' <span class=\"vc-rcard-unit\">MPa<\/span>';$('vc-r-fraction').innerHTML=fmt(pct,6)+'<span class=\"vc-rcard-unit\">%<\/span>';$('vc-results').classList.add('vc-visible');var u=new URL(location);u.searchParams.set('stress_area',As);u.searchParams.set('reference_stress',stress);u.searchParams.set('load_fraction',pct);history.replaceState(null,'',u.toString())}$('vc-form').addEventListener('input',calculate);$('vc-form').addEventListener('change',calculate);$('vc-copy-btn').addEventListener('click',function(){var t='Axial reference-load fraction\\nAs='+$('vc-area').value+' mm\u00b2\\nReference stress='+$('vc-stress').value+' MPa\\nFraction='+$('vc-fraction').value+'%\\nSelected load='+$('vc-r-load').textContent+'\\nThis is not a joint preload or torque design.';if(navigator.clipboard)navigator.clipboard.writeText(t)});document.querySelectorAll('.vc-section-toggle').forEach(function(b){b.addEventListener('click',function(){var s=this.closest('.vc-section');s.classList.toggle('vc-open');this.setAttribute('aria-expanded',s.classList.contains('vc-open'))})});var faqData=[{q:'Does ISO 898-1 specify preload or torque?',a:'<p>No. It specifies fastener mechanical\/physical properties and excludes torque\/clamp-force performance.<\/p>'},{q:'Can this result be my assembly target?',a:'<p>Not without complete joint design and a qualified tightening method including scatter and verification.<\/p>'},{q:'Why is there no K factor?',a:'<p>Generic K presets do not establish actual friction or torque\/clamp behaviour. Use qualified procedure or test data.<\/p>'}];var fl=$('vc-faq-list');faqData.forEach(function(f){fl.innerHTML+='<div class=\"vc-faq-item\"><button type=\"button\" class=\"vc-faq-q\"><span>'+f.q+'<\/span><\/button><div class=\"vc-faq-a\"><div class=\"vc-faq-a-inner\">'+f.a+'<\/div><\/div><\/div>'});fl.addEventListener('click',function(e){var b=e.target.closest('.vc-faq-q');if(b)b.closest('.vc-faq-item').classList.toggle('vc-open')});function load(){var p=new URLSearchParams(location.search);if(p.has('stress_area'))$('vc-area').value=p.get('stress_area');if(p.has('reference_stress'))$('vc-stress').value=p.get('reference_stress');if(p.has('load_fraction'))$('vc-fraction').value=p.get('load_fraction')}function init(){load();calculate()}if(document.readyState==='loading')document.addEventListener('DOMContentLoaded',init);else init()})();<\/script>\r\n","protected":false},"excerpt":{"rendered":"<p>Calculate a fraction of user-supplied reference stress times tensile stress area, with explicit ISO\/VDI applicability limits and no generic torque recommendation.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"ai_generated_summary":"","footnotes":""},"categories":[],"tags":[],"class_list":["post-100040","calculator","type-calculator","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/vibromera.eu\/bg\/wp-json\/wp\/v2\/calculator\/100040","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vibromera.eu\/bg\/wp-json\/wp\/v2\/calculator"}],"about":[{"href":"https:\/\/vibromera.eu\/bg\/wp-json\/wp\/v2\/types\/calculator"}],"version-history":[{"count":2,"href":"https:\/\/vibromera.eu\/bg\/wp-json\/wp\/v2\/calculator\/100040\/revisions"}],"predecessor-version":[{"id":102331,"href":"https:\/\/vibromera.eu\/bg\/wp-json\/wp\/v2\/calculator\/100040\/revisions\/102331"}],"wp:attachment":[{"href":"https:\/\/vibromera.eu\/bg\/wp-json\/wp\/v2\/media?parent=100040"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vibromera.eu\/bg\/wp-json\/wp\/v2\/categories?post=100040"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vibromera.eu\/bg\/wp-json\/wp\/v2\/tags?post=100040"}],"curies":[{"name":"\u0440\u0430\u0431\u043e\u0442\u043d\u0430 \u0441\u0440\u0435\u0449\u0430","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}