{"id":100236,"date":"2026-02-15T20:29:08","date_gmt":"2026-02-15T20:29:08","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100236"},"modified":"2026-02-15T20:29:08","modified_gmt":"2026-02-15T20:29:08","slug":"spline-connection-calculator","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/bn\/calculators\/spline-connection-calculator\/","title":{"rendered":"Spline Connection Calculator ISO 4156 | Free Tool #075"},"content":{"rendered":"\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"WebApplication\",\"name\":\"Spline Connection Calculator\",\"description\":\"ISO 4156 involute spline calculator.\",\"url\":\"https:\/\/vibromera.eu\/calculators\/spline-connection-calculator\/\",\"applicationCategory\":\"Engineering Calculator\",\"offers\":{\"@type\":\"Offer\",\"price\":\"0\",\"priceCurrency\":\"EUR\"},\"creator\":{\"@type\":\"Organization\",\"name\":\"Vibromera\"},\"datePublished\":\"2024-01-01\",\"dateModified\":\"2025-02-14\",\"inLanguage\":\"en\",\"isAccessibleForFree\":true}<\/script>\n\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"When to use splines vs keys?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Splines for higher torque, self-centering, sliding connections. Keys for simpler, lower-cost applications.\"}},{\"@type\":\"Question\",\"name\":\"What is the pressure angle effect?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"30 degrees standard. Higher angles give stronger teeth but more radial force.\"}},{\"@type\":\"Question\",\"name\":\"What load distribution factor?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"K=0.75 for fixed splines, K=0.5 for sliding under load.\"}},{\"@type\":\"Question\",\"name\":\"How long should engagement be?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"0.75D to 1.25D pitch diameters.\"}},{\"@type\":\"Question\",\"name\":\"What materials work best?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Case-hardened alloy steel 58-62 HRC for high loads.\"}}]}<\/script>\n\n<script type=\"application\/ld+json\">{\"@context\":\"https:\/\/schema.org\",\"@type\":\"BreadcrumbList\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/vibromera.eu\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Calculators\",\"item\":\"https:\/\/vibromera.eu\/calculators\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Spline 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var(--vc-border);border-radius:6px;padding:14px 20px;text-align:center;margin:14px 0;overflow-x:auto}.vc-warning-box{background:var(--vc-yellow-light);border-left:3px solid var(--vc-yellow);padding:14px 16px;border-radius:0 6px 6px 0;margin:14px 0}.vc-faq-list{display:flex;flex-direction:column;gap:8px;margin-top:20px}.vc-faq-item{border:1px solid var(--vc-border-light);border-radius:6px;overflow:hidden}.vc-faq-q{width:100%;display:flex;align-items:center;justify-content:space-between;gap:12px;padding:14px 16px;border:none;background:var(--vc-surface-alt);cursor:pointer;font-size:15px;font-weight:600;color:var(--vc-ink);text-align:left}.vc-faq-q:hover{background:#ede9e3}.vc-faq-chevron{width:16px;height:16px;color:var(--vc-ink-muted);transition:transform .25s}.vc-faq-item.vc-open .vc-faq-chevron{transform:rotate(180deg)}.vc-faq-a{max-height:0;overflow:hidden;transition:max-height .35s}.vc-faq-item.vc-open .vc-faq-a{max-height:1200px}.vc-faq-a-inner{padding:14px 16px;border-top:1px solid var(--vc-border-light);font-size:14px;color:var(--vc-ink-secondary)}.vc-faq-a-inner p{margin:0 0 8px}.vc-faq-a-inner p:last-child{margin-bottom:0}.vc-related{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px}.vc-related-link{display:inline-block;padding:8px 16px;font-size:13px;font-weight:600;background:var(--vc-surface-alt);color:var(--vc-ink-secondary);border:1px solid var(--vc-border);border-radius:var(--vc-radius);text-decoration:none}.vc-related-link:hover{border-color:var(--vc-accent);color:var(--vc-accent)}.vc-promo{margin-top:24px;padding:20px;background:linear-gradient(135deg,var(--vc-accent-light),var(--vc-surface));border:1px solid var(--vc-border);border-radius:var(--vc-radius-lg);display:flex;align-items:center;gap:16px}.vc-promo-text{flex:1;font-size:14px;color:var(--vc-ink-secondary)}.vc-promo-text strong{color:var(--vc-ink)}.vc-promo-link{padding:8px 20px;font-size:13px;font-weight:700;color:#fff;background:var(--vc-accent);border-radius:var(--vc-radius);text-decoration:none}.vc-footer{text-align:center;padding:32px 16px;font-size:13px;color:var(--vc-ink-muted)}.vc-footer a{color:var(--vc-accent);text-decoration:none}.vc-footer-links{margin-top:8px;font-size:12px}.vc-footer-links a{margin:0 8px}@media print{.vc-section-body{max-height:none!important}.vc-results{max-height:none!important;padding:24px!important}.vc-copy-btn,.vc-presets,.vc-promo{display:none!important}}<\/style>\n\n<div class=\"vc-calculator\">\n<header class=\"vc-header\"><p class=\"vc-header-eyebrow\">Free Engineering Tool #075<\/p><h1 class=\"vc-header-title\">Spline Connection Calculator &mdash; ISO 4156<\/h1><p class=\"vc-header-subtitle\">ISO 4156 involute spline design. Enter module, number of teeth, pressure angle, engagement length, and torque to calculate load capacity and bearing stress.<\/p><div class=\"vc-badges\"><span class=\"vc-badge\">ISO 4156<\/span><span class=\"vc-badge\">Involute Spline<\/span><span class=\"vc-badge\">Auto-Calc<\/span><\/div><\/header>\n<div class=\"vc-card\">\n<form class=\"vc-form\" id=\"vc-form\" autocomplete=\"off\"><div class=\"vc-form-grid\">\n<div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-mod\">Module m <span class=\"vc-label-hint\">(mm)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-mod\" step=\"any\" min=\"0.5\" value=\"2\"><\/div>\n<div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-z\">Number of Teeth z<\/label><input class=\"vc-input\" type=\"number\" id=\"vc-z\" step=\"1\" min=\"6\" value=\"20\"><\/div>\n<div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-pa\">Pressure Angle<\/label><select class=\"vc-select\" id=\"vc-pa\"><option value=\"30\" selected>30&deg;<\/option><option value=\"37.5\">37.5&deg;<\/option><option value=\"45\">45&deg;<\/option><\/select><\/div>\n<div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-len\">Engagement Length <span class=\"vc-label-hint\">(mm)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-len\" step=\"any\" min=\"1\" value=\"40\"><\/div>\n<div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-torque\">Torque <span class=\"vc-label-hint\">(N&middot;m)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-torque\" step=\"any\" min=\"0\" value=\"500\"><\/div>\n<div class=\"vc-field\"><label class=\"vc-label\" for=\"vc-sigall\">Allowable Bearing <span class=\"vc-label-hint\">(MPa)<\/span><\/label><input class=\"vc-input\" type=\"number\" id=\"vc-sigall\" step=\"any\" min=\"1\" value=\"100\"><\/div>\n<\/div>\n<div class=\"vc-presets\"><div class=\"vc-presets-label\">Quick presets<\/div>\n<button type=\"button\" class=\"vc-preset-btn\" data-m=\"2\" data-z=\"20\" data-l=\"40\" data-t=\"500\">m2 z20 L40 T500<\/button>\n<button type=\"button\" class=\"vc-preset-btn\" data-m=\"3\" data-z=\"16\" data-l=\"50\" data-t=\"1500\">m3 z16 L50 T1500<\/button>\n<button type=\"button\" class=\"vc-preset-btn\" data-m=\"1.5\" data-z=\"30\" data-l=\"30\" data-t=\"200\">m1.5 z30 L30 T200<\/button>\n<\/div><\/form>\n<div class=\"vc-results\" id=\"vc-results\"><div class=\"vc-results-head\"><h2 class=\"vc-results-title\">Results<\/h2><button type=\"button\" class=\"vc-copy-btn\" id=\"vc-copy-btn\">Copy<\/button><\/div>\n<div class=\"vc-result-grid\">\n<div class=\"vc-rcard vc-rcard-primary\"><div class=\"vc-rcard-label\">Torque Capacity<\/div><div class=\"vc-rcard-value\" id=\"vc-r-cap\">&mdash;<\/div><\/div>\n<div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Pitch Diameter<\/div><div class=\"vc-rcard-value\" id=\"vc-r-Dp\">&mdash;<\/div><\/div>\n<div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Bearing Stress<\/div><div class=\"vc-rcard-value\" id=\"vc-r-sig\">&mdash;<\/div><\/div>\n<div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Safety Factor<\/div><div class=\"vc-rcard-value\" id=\"vc-r-sf\">&mdash;<\/div><\/div>\n<div class=\"vc-rcard\"><div class=\"vc-rcard-label\">Root Diameter<\/div><div class=\"vc-rcard-value\" id=\"vc-r-Dr\">&mdash;<\/div><\/div>\n<\/div><\/div><\/div>\n<div class=\"vc-section vc-open\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"true\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">&#x1F4D8;<\/span><span class=\"vc-section-title\">Theory &amp; Formulas<\/span><\/span><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><\/button>\n<div class=\"vc-section-body\"><div class=\"vc-section-inner vc-theory\">\n<h3>Pitch Diameter<\/h3><div class=\"vc-formula-box\" id=\"vc-katex-1\"><\/div>\n<h3>Bearing Stress<\/h3><div class=\"vc-formula-box\" id=\"vc-katex-2\"><\/div>\n<p>where h = effective tooth height (approx 0.9m), z = teeth, L = engagement length, K = load distribution factor, Dp = pitch diameter.<\/p>\n<div class=\"vc-warning-box\"><p style=\"margin:0;font-size:14px;color:var(--vc-ink-secondary)\">Load distribution: K=0.75 fixed, K=0.5 sliding under load. This calculator uses K=0.75.<\/p><\/div>\n<\/div><\/div><\/div>\n<div class=\"vc-section\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">&#x1F517;<\/span><span class=\"vc-section-title\">Related<\/span><\/span><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><\/button><div class=\"vc-section-body\"><div class=\"vc-section-inner\"><div class=\"vc-related\"><a class=\"vc-related-link\" href=\"\/calculators\/keyway-calculator\/\">Keyway Calculator<\/a><a class=\"vc-related-link\" href=\"\/calculators\/shaft-diameter-torsion\/\">Shaft Diameter<\/a><a class=\"vc-related-link\" href=\"\/calculators\/press-fit-calculator\/\">Press Fit<\/a><\/div><\/div><\/div><\/div>\n<div class=\"vc-section\"><button type=\"button\" class=\"vc-section-toggle\" aria-expanded=\"false\"><span class=\"vc-section-toggle-text\"><span class=\"vc-section-icon\">&#x2753;<\/span><span class=\"vc-section-title\">FAQ<\/span><\/span><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><\/button><div class=\"vc-section-body\"><div class=\"vc-section-inner\"><div class=\"vc-faq-list\" id=\"vc-faq-list\"><\/div><\/div><\/div><\/div>\n<div class=\"vc-promo\"><div class=\"vc-promo-text\"><strong>Vibromera<\/strong> &mdash; Portable Balancing &amp; Vibration Analysis.<\/div><a class=\"vc-promo-link\" href=\"https:\/\/vibromera.eu\/\" target=\"_blank\" rel=\"noopener\">Learn More<\/a><\/div>\n<footer class=\"vc-footer\"><p>&copy; 2024&ndash;2025 <a href=\"https:\/\/vibromera.eu\/\">Vibromera<\/a><\/p><div class=\"vc-footer-links\"><a href=\"\/calculators\/engineering-calculators\/\">All Calculators<\/a><a href=\"https:\/\/vibromera.eu\/contacts\/\">Contact<\/a><\/div><\/footer>\n<\/div>\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/katex@0.16.11\/dist\/katex.min.js\"><\/script>\n<script>\n(function(){\n'use strict';var SLUG='spline-connection-calculator';\nfunction $(id){return document.getElementById(id)}\nfunction fmt(n,d){if(isNaN(n)||!isFinite(n))return'\\u2014';return n.toFixed(d==null?2:d).replace(\/(\\.\\d*?)0+$\/,'$1').replace(\/\\.$\/,'')}\nfunction calc(){\n  var m=parseFloat($('vc-mod').value),z=parseInt($('vc-z').value),L=parseFloat($('vc-len').value),T=parseFloat($('vc-torque').value),sigA=parseFloat($('vc-sigall').value);\n  if(!m||m<=0||!z||z<6||!L||L<=0||!T||T<=0||!sigA){$('vc-results').classList.remove('vc-visible');return}\n  var Tmm=T*1000,Dp=m*z,h=0.9*m,K=0.75;\n  var sig=2*Tmm\/(Dp*z*h*L*K);\n  var Tcap=sigA*z*h*L*K*Dp\/2\/1000;\n  var sf=Tcap*1000\/(Tmm);\n  var Dr=Dp-2*1.25*m;\n  $('vc-r-cap').innerHTML=fmt(Tcap,0)+' <span class=\"vc-rcard-unit\">N\\u00B7m<\/span>';\n  $('vc-r-Dp').innerHTML=fmt(Dp,1)+' <span class=\"vc-rcard-unit\">mm<\/span>';\n  $('vc-r-sig').innerHTML=fmt(sig,1)+' <span class=\"vc-rcard-unit\">MPa<\/span>';\n  $('vc-r-sf').innerHTML=fmt(sf,2)+(sf<1?' <span style=\"color:var(--vc-red)\">INSUFFICIENT<\/span>':' <span style=\"color:var(--vc-green)\">OK<\/span>');\n  $('vc-r-Dr').innerHTML=fmt(Dr,1)+' <span class=\"vc-rcard-unit\">mm<\/span>';\n  $('vc-results').classList.add('vc-visible');\n  sH({m:m,z:z,T:T,_summary:'m='+m+' z='+z+' T='+T});\n}\ndocument.querySelectorAll('.vc-preset-btn').forEach(function(b){b.addEventListener('click',function(e){e.preventDefault();$('vc-mod').value=this.getAttribute('data-m');$('vc-z').value=this.getAttribute('data-z');$('vc-len').value=this.getAttribute('data-l');$('vc-torque').value=this.getAttribute('data-t');calc()})});\n$('vc-form').addEventListener('input',calc);$('vc-form').addEventListener('change',calc);\n$('vc-copy-btn').addEventListener('click',function(){var t='Spline Connection\\nCapacity: '+$('vc-r-cap').textContent+'\\nDp: '+$('vc-r-Dp').textContent+'\\nStress: '+$('vc-r-sig').textContent+'\\nSF: '+$('vc-r-sf').textContent;if(navigator.clipboard){navigator.clipboard.writeText(t).then(function(){var b=$('vc-copy-btn');b.classList.add('vc-copied');b.textContent='Copied!';setTimeout(function(){b.classList.remove('vc-copied');b.textContent='Copy'},2000)})}});\ndocument.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'))})});\nvar fD=[{q:'Splines vs keys?',a:'<p>Splines for higher torque, self-centering, sliding. Keys for simpler apps.<\/p>'},{q:'Pressure angle effect?',a:'<p>30\\u00B0 standard. 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