Shaft Strength Calculator<\/title>\n <link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\" \/>\n <link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin \/>\n <link href=\"https:\/\/fonts.googleapis.com\/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap\" rel=\"stylesheet\" \/>\n <style>\n \/*\n No Tailwind \/ no third-party CSS framework \u2014 everything is scoped under #ssc-shaft-calc\n so WordPress themes, comments, and footers are never affected.\n *\/\n #ssc-shaft-calc.ssc-root {\n --ssc-text: #1e293b;\n --ssc-muted: #64748b;\n --ssc-label: #334155;\n --ssc-blue: #1e40af;\n --ssc-border: #cbd5e1;\n --ssc-amber-bg: #fffbeb;\n --ssc-amber-border: #fcd34d;\n --ssc-amber-text: #92400e;\n\n isolation: isolate;\n contain: layout style;\n box-sizing: border-box;\n width: 100%;\n max-width: 42rem;\n margin-left: auto;\n margin-right: auto;\n padding: 2rem 1rem;\n font-family: Inter, system-ui, sans-serif;\n font-size: 1rem;\n line-height: 1.5;\n color: var(--ssc-text);\n -webkit-font-smoothing: antialiased;\n background: #fff;\n }\n\n #ssc-shaft-calc.ssc-root *,\n #ssc-shaft-calc.ssc-root *::before,\n #ssc-shaft-calc.ssc-root *::after {\n box-sizing: border-box;\n }\n\n #ssc-shaft-calc .ssc-card-border {\n border: 1px solid rgba(30, 58, 95, 0.25);\n border-radius: 0.75rem;\n box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);\n background: #fff;\n padding: 1.5rem;\n }\n @media (min-width: 768px) {\n #ssc-shaft-calc .ssc-card-border {\n padding: 2rem;\n }\n }\n\n #ssc-shaft-calc .ssc-title {\n margin: 0 0 1.5rem 0;\n font-size: 0.875rem;\n font-weight: 600;\n color: #1e3a5f;\n text-transform: uppercase;\n letter-spacing: 0.05em;\n }\n\n #ssc-shaft-calc .ssc-form > * + * {\n margin-top: 1.5rem;\n }\n\n #ssc-shaft-calc .ssc-label {\n display: block;\n margin-bottom: 0.25rem;\n font-size: 0.875rem;\n font-weight: 500;\n color: var(--ssc-label);\n }\n\n #ssc-shaft-calc .ssc-mono {\n font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;\n }\n\n #ssc-shaft-calc .ssc-input-row {\n display: grid !important;\n grid-template-columns: minmax(0, 76fr) minmax(5.75rem, 24fr);\n gap: 0.5rem;\n align-items: stretch;\n width: 100%;\n min-width: 0;\n }\n\n #ssc-shaft-calc .ssc-input-row .ssc-num-input {\n width: 100% !important;\n min-width: 0 !important;\n max-width: none !important;\n height: 2.5rem;\n margin: 0;\n padding: 0 0.75rem;\n border: 1px solid var(--ssc-border);\n border-radius: 0.5rem;\n background-color: #fff !important;\n font-size: 0.875rem;\n font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;\n color: var(--ssc-text);\n }\n\n #ssc-shaft-calc .ssc-input-row .ssc-unit-select {\n width: 100% !important;\n min-width: 5.75rem !important;\n max-width: none !important;\n height: 2.5rem;\n margin: 0;\n padding: 0 1.5rem 0 0.5rem;\n border: 1px solid var(--ssc-border);\n border-radius: 0.5rem;\n background-color: #fff !important;\n font-size: 0.875rem;\n font-family: inherit;\n color: var(--ssc-text);\n line-height: normal;\n cursor: pointer;\n appearance: auto;\n overflow: visible !important;\n text-overflow: clip !important;\n white-space: nowrap;\n }\n\n #ssc-shaft-calc .ssc-field-select,\n #ssc-shaft-calc .ssc-field-input {\n width: 100% !important;\n max-width: 100% !important;\n min-height: 2.5rem;\n margin: 0;\n border: 1px solid var(--ssc-border) !important;\n border-radius: 0.5rem !important;\n background-color: #fff !important;\n font-size: 0.875rem;\n color: var(--ssc-text);\n outline: none;\n }\n #ssc-shaft-calc .ssc-field-select {\n padding: 0.375rem 0.75rem;\n cursor: pointer;\n appearance: auto;\n }\n #ssc-shaft-calc .ssc-field-input {\n padding: 0 0.75rem;\n font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;\n }\n\n #ssc-shaft-calc .ssc-grid-2 {\n display: grid;\n grid-template-columns: minmax(0, 1fr);\n gap: 1rem;\n width: 100%;\n min-width: 0;\n }\n @media (min-width: 640px) {\n #ssc-shaft-calc .ssc-grid-2 {\n grid-template-columns: repeat(2, minmax(0, 1fr));\n column-gap: 2rem;\n row-gap: 1rem;\n }\n }\n #ssc-shaft-calc .ssc-grid-2 > div {\n min-width: 0;\n }\n\n #ssc-shaft-calc .ssc-num-input:focus,\n #ssc-shaft-calc .ssc-unit-select:focus,\n #ssc-shaft-calc .ssc-field-select:focus,\n #ssc-shaft-calc .ssc-field-input:focus {\n outline: none !important;\n border-color: #2563eb !important;\n box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2) !important;\n }\n\n #ssc-shaft-calc .ssc-hint {\n margin: 0.25rem 0 0 0;\n font-size: 0.75rem;\n color: var(--ssc-muted);\n }\n\n #ssc-shaft-calc .ssc-btn-wrap {\n display: flex;\n justify-content: center;\n padding-top: 0.5rem;\n }\n\n #ssc-shaft-calc .ssc-calc-btn {\n display: inline-flex;\n align-items: center;\n justify-content: center;\n margin: 0;\n padding: 0.875rem 2.5rem;\n font-size: 1rem;\n font-weight: 600;\n font-family: inherit;\n line-height: 1.25;\n border-radius: 0.5rem;\n cursor: pointer;\n color: #ffffff !important;\n background-color: #1e40af !important;\n border: 1px solid transparent !important;\n text-decoration: none !important;\n box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);\n }\n #ssc-shaft-calc .ssc-calc-btn:hover,\n #ssc-shaft-calc .ssc-calc-btn:focus {\n color: #ffffff !important;\n background-color: #1e3a8a !important;\n border-color: transparent !important;\n outline: none !important;\n box-shadow: 0 1px 2px rgba(0, 0, 0, 0.12) !important;\n }\n #ssc-shaft-calc .ssc-calc-btn:focus-visible {\n outline: 2px solid #2563eb !important;\n outline-offset: 2px;\n }\n\n #ssc-shaft-calc .ssc-results {\n margin-top: 2rem;\n padding-top: 2rem;\n border-top: 1px solid #e2e8f0;\n }\n #ssc-shaft-calc .ssc-results-title {\n margin: 0 0 1rem 0;\n font-size: 0.875rem;\n font-weight: 600;\n color: #1e3a5f;\n text-transform: uppercase;\n letter-spacing: 0.05em;\n }\n #ssc-shaft-calc .ssc-dl {\n margin: 0;\n }\n #ssc-shaft-calc .ssc-dl > * + * {\n margin-top: 0.75rem;\n }\n #ssc-shaft-calc .ssc-result-row {\n display: flex;\n justify-content: space-between;\n gap: 1rem;\n padding: 0.5rem 0;\n border-bottom: 1px solid #f1f5f9;\n font-size: 0.875rem;\n font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;\n }\n #ssc-shaft-calc .ssc-result-row dt {\n margin: 0;\n color: var(--ssc-muted);\n }\n #ssc-shaft-calc .ssc-result-row dd {\n margin: 0;\n text-align: right;\n }\n #ssc-shaft-calc .ssc-result-row .ssc-dd-strong {\n font-weight: 600;\n color: var(--ssc-text);\n }\n #ssc-shaft-calc .ssc-result-row .ssc-dd-blue {\n font-weight: 700;\n font-size: 1rem;\n color: var(--ssc-blue);\n }\n #ssc-shaft-calc .ssc-formula-note {\n margin: 1rem 0 0 0;\n font-size: 0.75rem;\n color: var(--ssc-muted);\n line-height: 1.6;\n }\n #ssc-shaft-calc .ssc-te-note {\n display: block;\n margin-top: 0.25rem;\n color: var(--ssc-muted);\n font-size: 0.75rem;\n font-weight: normal;\n font-family: Inter, system-ui, sans-serif;\n }\n @media (min-width: 640px) {\n #ssc-shaft-calc .ssc-te-note {\n display: inline;\n margin-top: 0;\n margin-left: 0.25rem;\n }\n }\n\n #ssc-shaft-calc .ssc-error {\n margin-top: 1.5rem;\n padding: 0.75rem 1rem;\n font-size: 0.875rem;\n color: var(--ssc-amber-text);\n background: var(--ssc-amber-bg);\n border: 1px solid var(--ssc-amber-border);\n border-radius: 0.5rem;\n }\n\n #ssc-shaft-calc .ssc-hidden {\n display: none !important;\n }\n <\/style>\n<\/head>\n<body>\n <div id=\"ssc-shaft-calc\" class=\"ssc-root\">\n <section class=\"ssc-card-border\">\n <h2 class=\"ssc-title\">Input parameters<\/h2>\n <form id=\"calcForm\" class=\"ssc-form\">\n <div class=\"ssc-grid-2\">\n <div>\n <label for=\"moment\" class=\"ssc-label\">Bending moment <span class=\"ssc-mono\">M<\/span><\/label>\n <div class=\"ssc-input-row\">\n <input type=\"number\" id=\"moment\" name=\"moment\" step=\"any\" min=\"0\" placeholder=\"e.g. 1200\" class=\"ssc-num-input\" \/>\n <select id=\"momentUnit\" class=\"ssc-unit-select\">\n <option value=\"Nm\">N\u00b7m<\/option>\n <option value=\"lbin\">lb\u00b7in<\/option>\n <\/select>\n <\/div>\n <\/div>\n <div>\n <label for=\"torque\" class=\"ssc-label\">Torque \/ torsion <span class=\"ssc-mono\">T<\/span><\/label>\n <div class=\"ssc-input-row\">\n <input type=\"number\" id=\"torque\" name=\"torque\" step=\"any\" min=\"0\" placeholder=\"e.g. 800\" class=\"ssc-num-input\" \/>\n <select id=\"torqueUnit\" class=\"ssc-unit-select\">\n <option value=\"Nm\">N\u00b7m<\/option>\n <option value=\"lbin\">lb\u00b7in<\/option>\n <\/select>\n <\/div>\n <\/div>\n <\/div>\n\n <div>\n <label for=\"material\" class=\"ssc-label\">Material library \u2014 allowable shear stress <span class=\"ssc-mono\">[\u03c4]<\/span><\/label>\n <select id=\"material\" class=\"ssc-field-select\">\n <option value=\"custom\">Custom value (manual entry below)<\/option>\n <option value=\"45\" data-mpa=\"40\" data-note=\"45# steel, normalized \/ typical shaft\">45# steel (normalized) \u2014 40 MPa<\/option>\n <option value=\"40cr\" data-mpa=\"55\" data-note=\"40Cr alloy, Q&T \u2014 indicative\">40Cr (quenched & tempered) \u2014 55 MPa<\/option>\n <option value=\"304\" data-mpa=\"35\" data-note=\"AISI 304 \u2014 conservative\">304 stainless steel \u2014 35 MPa<\/option>\n <option value=\"316\" data-mpa=\"38\" data-note=\"AISI 316\">316 stainless steel \u2014 38 MPa<\/option>\n <option value=\"q235\" data-mpa=\"32\" data-note=\"Q235 structural \u2014 conservative\">Q235 \u2014 32 MPa<\/option>\n <option value=\"6061\" data-mpa=\"55\" data-note=\"6061-T6 aluminum \u2014 verify for shafts\">6061-T6 aluminum \u2014 55 MPa<\/option>\n <\/select>\n <p id=\"materialNote\" class=\"ssc-hint ssc-hidden\"><\/p>\n <\/div>\n\n <div class=\"ssc-grid-2\">\n <div>\n <label for=\"tau\" class=\"ssc-label\">Allowable shear stress <span class=\"ssc-mono\">[\u03c4]<\/span><\/label>\n <div class=\"ssc-input-row\">\n <input type=\"number\" id=\"tau\" name=\"tau\" step=\"any\" min=\"0\" placeholder=\"40\" class=\"ssc-num-input\" \/>\n <select id=\"tauUnit\" class=\"ssc-unit-select\">\n <option value=\"MPa\">MPa<\/option>\n <option value=\"psi\">psi<\/option>\n <\/select>\n <\/div>\n <\/div>\n <div>\n <label for=\"safety\" class=\"ssc-label\">Safety factor <span class=\"ssc-mono\">S<\/span><\/label>\n <input type=\"number\" id=\"safety\" name=\"safety\" step=\"any\" min=\"0.1\" value=\"1.5\" class=\"ssc-field-input\" \/>\n <p class=\"ssc-hint\">Uses design stress <span class=\"ssc-mono\">[\u03c4]\/S<\/span> (larger S \u2192 larger d).<\/p>\n <\/div>\n <\/div>\n\n <div class=\"ssc-btn-wrap\">\n <button type=\"submit\" class=\"ssc-calc-btn\">Calculate<\/button>\n <\/div>\n <\/form>\n\n <div id=\"resultPanel\" class=\"ssc-results ssc-hidden\">\n <h3 class=\"ssc-results-title\">Detailed results<\/h3>\n <dl class=\"ssc-dl\">\n <div class=\"ssc-result-row\">\n <dt>Equivalent torque <span style=\"color: #1e40af\">T<sub>e<\/sub><\/span><\/dt>\n <dd id=\"outTe\" class=\"ssc-dd-strong\"><\/dd>\n <\/div>\n <div class=\"ssc-result-row\">\n <dt>Design allowable shear <span style=\"color: #1e40af\">[\u03c4]\/S<\/span><\/dt>\n <dd id=\"outTauDesign\"><\/dd>\n <\/div>\n <div class=\"ssc-result-row\">\n <dt>Minimum required diameter <span style=\"color: #1e40af\">d<\/span><\/dt>\n <dd id=\"outD\" class=\"ssc-dd-blue\"><\/dd>\n <\/div>\n <\/dl>\n <p id=\"formulaNote\" class=\"ssc-formula-note\"><\/p>\n <\/div>\n\n <div id=\"errorBox\" class=\"ssc-error ssc-hidden\"><\/div>\n <\/section>\n <\/div>\n\n <script>\n (function () {\n const Nm_PER_lbin = 0.112984829;\n const PSI_PER_MPA = 145.0377377;\n\n const el = (id) => document.getElementById(id);\n\n function toNm(value, unit) {\n if (unit === 'lbin') return value * Nm_PER_lbin;\n return value;\n }\n\n function toPa(value, unit) {\n if (unit === 'psi') return value * 6894.757293168;\n return value * 1e6;\n }\n\n function formatNum(n, digits) {\n if (!isFinite(n)) return '\u2014';\n const abs = Math.abs(n);\n if (abs >= 1000 || (abs > 0 && abs < 0.01)) return n.toExponential(digits ?? 4);\n return n.toFixed(digits ?? 3).replace(\/\\.?0+$\/, '') || '0';\n }\n\n function compute() {\n const mRaw = parseFloat(el('moment').value);\n const tRaw = parseFloat(el('torque').value);\n const tauRaw = parseFloat(el('tau').value);\n const sRaw = parseFloat(el('safety').value);\n const mUnit = el('momentUnit').value;\n const tUnit = el('torqueUnit').value;\n const tauUnit = el('tauUnit').value;\n\n el('errorBox').classList.add('ssc-hidden');\n el('resultPanel').classList.add('ssc-hidden');\n\n if ([mRaw, tRaw, tauRaw, sRaw].some((v) => Number.isNaN(v))) {\n el('errorBox').textContent = 'Please enter valid numbers for M, T, [\u03c4], and S.';\n el('errorBox').classList.remove('ssc-hidden');\n return;\n }\n if (mRaw < 0 || tRaw < 0 || tauRaw <= 0 || sRaw <= 0) {\n el('errorBox').textContent = 'M and T must be \u2265 0; [\u03c4] and S must be positive.';\n el('errorBox').classList.remove('ssc-hidden');\n return;\n }\n\n const M = toNm(mRaw, mUnit);\n const T = toNm(tRaw, tUnit);\n const tauAllowPa = toPa(tauRaw, tauUnit);\n const S = sRaw;\n const tauDesignPa = tauAllowPa \/ S;\n\n const Te = Math.sqrt(M * M + T * T);\n const dM = Math.pow((16 * Te) \/ (Math.PI * tauDesignPa), 1 \/ 3);\n\n const displayTauUnit = tauUnit;\n const TeLbIn = Te \/ Nm_PER_lbin;\n const dInch = dM \/ 0.0254;\n\n el('outTe').innerHTML =\n formatNum(Te, 4) +\n ' N\u00b7m \u00b7 ' +\n formatNum(TeLbIn, 4) +\n ' lb\u00b7in <span class=\"ssc-te-note\">T<sub>e<\/sub> = \u221a(M\u00b2 + T\u00b2) after converting M and T to SI.<\/span>';\n\n const tauDesignDisplay = tauUnit === 'psi' ? tauDesignPa \/ 6894.757293168 : tauDesignPa \/ 1e6;\n el('outTauDesign').textContent = formatNum(tauDesignDisplay, 4) + ' ' + displayTauUnit;\n\n const imperialPreferred = mUnit === 'lbin' && tUnit === 'lbin';\n el('outD').textContent = imperialPreferred\n ? formatNum(dInch, 4) + ' in \u00b7 ' + formatNum(dM * 1000, 3) + ' mm'\n : formatNum(dM * 1000, 3) + ' mm \u00b7 ' + formatNum(dInch, 4) + ' in';\n\n el('formulaNote').textContent =\n 'Tresca (maximum shear stress): d = \u221b(16\u00b7T_e\u00b7S \/ (\u03c0\u00b7[\u03c4])). Inputs converted to SI for the core calculation; results shown in your selected shaft units where applicable.';\n\n el('resultPanel').classList.remove('ssc-hidden');\n }\n\n el('material').addEventListener('change', function () {\n const opt = this.options[this.selectedIndex];\n const noteEl = el('materialNote');\n if (this.value === 'custom') {\n noteEl.classList.add('ssc-hidden');\n return;\n }\n const mpa = parseFloat(opt.getAttribute('data-mpa'));\n if (!Number.isNaN(mpa)) {\n if (el('tauUnit').value === 'MPa') el('tau').value = String(mpa);\n else el('tau').value = String((mpa * PSI_PER_MPA).toFixed(0));\n }\n const note = opt.getAttribute('data-note');\n if (note) {\n noteEl.textContent = note;\n noteEl.classList.remove('ssc-hidden');\n } else noteEl.classList.add('ssc-hidden');\n });\n\n el('tauUnit').addEventListener('change', function () {\n const tauIn = parseFloat(el('tau').value);\n if (Number.isNaN(tauIn) || tauIn <= 0) return;\n if (this.value === 'psi') el('tau').value = String((tauIn * PSI_PER_MPA).toFixed(2));\n else el('tau').value = String((tauIn \/ PSI_PER_MPA).toFixed(4));\n });\n\n el('calcForm').addEventListener('submit', function (e) {\n e.preventDefault();\n compute();\n });\n })();\n <\/script>\n<\/body>\n<\/html>\n\n","protected":false},"excerpt":{"rendered":"<p>The Shaft Strength & Diameter Calculator is an essential engineering tool designed to help mechanical engineers accurately determine the required shaft diameter based on torque,…<\/p>","protected":false},"author":2,"featured_media":24484,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"pmpro_default_level":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[8520],"tags":[8522,2940,8521],"class_list":["post-24483","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mechanical-basic-component-design","tag-diameter-sizing","tag-shaft-design","tag-strength-calc","pmpro-has-access"],"acf":[],"jetpack_featured_media_url":"https:\/\/www.mechstream.com\/wp-content\/uploads\/2026\/03\/Shaft-Strength-Diameter-Calculator.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts\/24483","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/comments?post=24483"}],"version-history":[{"count":0,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts\/24483\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/media\/24484"}],"wp:attachment":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/media?parent=24483"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/categories?post=24483"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/tags?post=24483"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}

{"id":24483,"date":"2026-03-24T03:04:18","date_gmt":"2026-03-24T03:04:18","guid":{"rendered":"https:\/\/www.mechstream.com\/?p=24483"},"modified":"2026-03-24T03:19:11","modified_gmt":"2026-03-24T03:19:11","slug":"shaft-strength-diameter-calculator","status":"publish","type":"post","link":"https:\/\/www.mechstream.com\/pt\/shaft-strength-diameter-calculator\/","title":{"rendered":"Shaft Strength & Diameter Calculator"},"content":{"rendered":"\n

The Shaft Strength & Diameter Calculator<\/strong> is an essential engineering tool designed to help mechanical engineers accurately determine the required shaft diameter based on torque, material properties, and safety factors. By simplifying complex strength calculations, this calculator ensures optimal shaft design for durability, performance, and reliability in various industrial applications. Widely used in machinery design, power transmission systems, and heavy equipment manufacturing, the Shaft Strength & Diameter Calculator<\/strong> helps prevent shaft failure, reduce material waste, and improve overall system efficiency. It is a must-have tool for engineers seeking precise and efficient shaft sizing solutions.<\/p>\n\n\n\n\n\n\n \n \n \n Shaft Strength Calculator<\/title>\n <link rel=\"preconnect\" href=\"https:\/\/fonts.googleapis.com\" \/>\n <link rel=\"preconnect\" href=\"https:\/\/fonts.gstatic.com\" crossorigin \/>\n <link href=\"https:\/\/fonts.googleapis.com\/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap\" rel=\"stylesheet\" \/>\n <style>\n \/*\n No Tailwind \/ no third-party CSS framework \u2014 everything is scoped under #ssc-shaft-calc\n so WordPress themes, comments, and footers are never affected.\n *\/\n #ssc-shaft-calc.ssc-root {\n --ssc-text: #1e293b;\n --ssc-muted: #64748b;\n --ssc-label: #334155;\n --ssc-blue: #1e40af;\n --ssc-border: #cbd5e1;\n --ssc-amber-bg: #fffbeb;\n --ssc-amber-border: #fcd34d;\n --ssc-amber-text: #92400e;\n\n isolation: isolate;\n contain: layout style;\n box-sizing: border-box;\n width: 100%;\n max-width: 42rem;\n margin-left: auto;\n margin-right: auto;\n padding: 2rem 1rem;\n font-family: Inter, system-ui, sans-serif;\n font-size: 1rem;\n line-height: 1.5;\n color: var(--ssc-text);\n -webkit-font-smoothing: antialiased;\n background: #fff;\n }\n\n #ssc-shaft-calc.ssc-root *,\n #ssc-shaft-calc.ssc-root *::before,\n #ssc-shaft-calc.ssc-root *::after {\n box-sizing: border-box;\n }\n\n #ssc-shaft-calc .ssc-card-border {\n border: 1px solid rgba(30, 58, 95, 0.25);\n border-radius: 0.75rem;\n box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);\n background: #fff;\n padding: 1.5rem;\n }\n @media (min-width: 768px) {\n #ssc-shaft-calc .ssc-card-border {\n padding: 2rem;\n }\n }\n\n #ssc-shaft-calc .ssc-title {\n margin: 0 0 1.5rem 0;\n font-size: 0.875rem;\n font-weight: 600;\n color: #1e3a5f;\n text-transform: uppercase;\n letter-spacing: 0.05em;\n }\n\n #ssc-shaft-calc .ssc-form > * + * {\n margin-top: 1.5rem;\n }\n\n #ssc-shaft-calc .ssc-label {\n display: block;\n margin-bottom: 0.25rem;\n font-size: 0.875rem;\n font-weight: 500;\n color: var(--ssc-label);\n }\n\n #ssc-shaft-calc .ssc-mono {\n font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;\n }\n\n #ssc-shaft-calc .ssc-input-row {\n display: grid !important;\n grid-template-columns: minmax(0, 76fr) minmax(5.75rem, 24fr);\n gap: 0.5rem;\n align-items: stretch;\n width: 100%;\n min-width: 0;\n }\n\n #ssc-shaft-calc .ssc-input-row .ssc-num-input {\n width: 100% !important;\n min-width: 0 !important;\n max-width: none !important;\n height: 2.5rem;\n margin: 0;\n padding: 0 0.75rem;\n border: 1px solid var(--ssc-border);\n border-radius: 0.5rem;\n background-color: #fff !important;\n font-size: 0.875rem;\n font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;\n color: var(--ssc-text);\n }\n\n #ssc-shaft-calc .ssc-input-row .ssc-unit-select {\n width: 100% !important;\n min-width: 5.75rem !important;\n max-width: none !important;\n height: 2.5rem;\n margin: 0;\n padding: 0 1.5rem 0 0.5rem;\n border: 1px solid var(--ssc-border);\n border-radius: 0.5rem;\n background-color: #fff !important;\n font-size: 0.875rem;\n font-family: inherit;\n color: var(--ssc-text);\n line-height: normal;\n cursor: pointer;\n appearance: auto;\n overflow: visible !important;\n text-overflow: clip !important;\n white-space: nowrap;\n }\n\n #ssc-shaft-calc .ssc-field-select,\n #ssc-shaft-calc .ssc-field-input {\n width: 100% !important;\n max-width: 100% !important;\n min-height: 2.5rem;\n margin: 0;\n border: 1px solid var(--ssc-border) !important;\n border-radius: 0.5rem !important;\n background-color: #fff !important;\n font-size: 0.875rem;\n color: var(--ssc-text);\n outline: none;\n }\n #ssc-shaft-calc .ssc-field-select {\n padding: 0.375rem 0.75rem;\n cursor: pointer;\n appearance: auto;\n }\n #ssc-shaft-calc .ssc-field-input {\n padding: 0 0.75rem;\n font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;\n }\n\n #ssc-shaft-calc .ssc-grid-2 {\n display: grid;\n grid-template-columns: minmax(0, 1fr);\n gap: 1rem;\n width: 100%;\n min-width: 0;\n }\n @media (min-width: 640px) {\n #ssc-shaft-calc .ssc-grid-2 {\n grid-template-columns: repeat(2, minmax(0, 1fr));\n column-gap: 2rem;\n row-gap: 1rem;\n }\n }\n #ssc-shaft-calc .ssc-grid-2 > div {\n min-width: 0;\n }\n\n #ssc-shaft-calc .ssc-num-input:focus,\n #ssc-shaft-calc .ssc-unit-select:focus,\n #ssc-shaft-calc .ssc-field-select:focus,\n #ssc-shaft-calc .ssc-field-input:focus {\n outline: none !important;\n border-color: #2563eb !important;\n box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.2) !important;\n }\n\n #ssc-shaft-calc .ssc-hint {\n margin: 0.25rem 0 0 0;\n font-size: 0.75rem;\n color: var(--ssc-muted);\n }\n\n #ssc-shaft-calc .ssc-btn-wrap {\n display: flex;\n justify-content: center;\n padding-top: 0.5rem;\n }\n\n #ssc-shaft-calc .ssc-calc-btn {\n display: inline-flex;\n align-items: center;\n justify-content: center;\n margin: 0;\n padding: 0.875rem 2.5rem;\n font-size: 1rem;\n font-weight: 600;\n font-family: inherit;\n line-height: 1.25;\n border-radius: 0.5rem;\n cursor: pointer;\n color: #ffffff !important;\n background-color: #1e40af !important;\n border: 1px solid transparent !important;\n text-decoration: none !important;\n box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);\n }\n #ssc-shaft-calc .ssc-calc-btn:hover,\n #ssc-shaft-calc .ssc-calc-btn:focus {\n color: #ffffff !important;\n background-color: #1e3a8a !important;\n border-color: transparent !important;\n outline: none !important;\n box-shadow: 0 1px 2px rgba(0, 0, 0, 0.12) !important;\n }\n #ssc-shaft-calc .ssc-calc-btn:focus-visible {\n outline: 2px solid #2563eb !important;\n outline-offset: 2px;\n }\n\n #ssc-shaft-calc .ssc-results {\n margin-top: 2rem;\n padding-top: 2rem;\n border-top: 1px solid #e2e8f0;\n }\n #ssc-shaft-calc .ssc-results-title {\n margin: 0 0 1rem 0;\n font-size: 0.875rem;\n font-weight: 600;\n color: #1e3a5f;\n text-transform: uppercase;\n letter-spacing: 0.05em;\n }\n #ssc-shaft-calc .ssc-dl {\n margin: 0;\n }\n #ssc-shaft-calc .ssc-dl > * + * {\n margin-top: 0.75rem;\n }\n #ssc-shaft-calc .ssc-result-row {\n display: flex;\n justify-content: space-between;\n gap: 1rem;\n padding: 0.5rem 0;\n border-bottom: 1px solid #f1f5f9;\n font-size: 0.875rem;\n font-family: 'JetBrains Mono', ui-monospace, Consolas, monospace;\n }\n #ssc-shaft-calc .ssc-result-row dt {\n margin: 0;\n color: var(--ssc-muted);\n }\n #ssc-shaft-calc .ssc-result-row dd {\n margin: 0;\n text-align: right;\n }\n #ssc-shaft-calc .ssc-result-row .ssc-dd-strong {\n font-weight: 600;\n color: var(--ssc-text);\n }\n #ssc-shaft-calc .ssc-result-row .ssc-dd-blue {\n font-weight: 700;\n font-size: 1rem;\n color: var(--ssc-blue);\n }\n #ssc-shaft-calc .ssc-formula-note {\n margin: 1rem 0 0 0;\n font-size: 0.75rem;\n color: var(--ssc-muted);\n line-height: 1.6;\n }\n #ssc-shaft-calc .ssc-te-note {\n display: block;\n margin-top: 0.25rem;\n color: var(--ssc-muted);\n font-size: 0.75rem;\n font-weight: normal;\n font-family: Inter, system-ui, sans-serif;\n }\n @media (min-width: 640px) {\n #ssc-shaft-calc .ssc-te-note {\n display: inline;\n margin-top: 0;\n margin-left: 0.25rem;\n }\n }\n\n #ssc-shaft-calc .ssc-error {\n margin-top: 1.5rem;\n padding: 0.75rem 1rem;\n font-size: 0.875rem;\n color: var(--ssc-amber-text);\n background: var(--ssc-amber-bg);\n border: 1px solid var(--ssc-amber-border);\n border-radius: 0.5rem;\n }\n\n #ssc-shaft-calc .ssc-hidden {\n display: none !important;\n }\n <\/style>\n<\/head>\n<body>\n <div id=\"ssc-shaft-calc\" class=\"ssc-root\">\n <section class=\"ssc-card-border\">\n <h2 class=\"ssc-title\">Input parameters<\/h2>\n <form id=\"calcForm\" class=\"ssc-form\">\n <div class=\"ssc-grid-2\">\n <div>\n <label for=\"moment\" class=\"ssc-label\">Bending moment <span class=\"ssc-mono\">M<\/span><\/label>\n <div class=\"ssc-input-row\">\n <input type=\"number\" id=\"moment\" name=\"moment\" step=\"any\" min=\"0\" placeholder=\"e.g. 1200\" class=\"ssc-num-input\" \/>\n <select id=\"momentUnit\" class=\"ssc-unit-select\">\n <option value=\"Nm\">N\u00b7m<\/option>\n <option value=\"lbin\">lb\u00b7in<\/option>\n <\/select>\n <\/div>\n <\/div>\n <div>\n <label for=\"torque\" class=\"ssc-label\">Torque \/ torsion <span class=\"ssc-mono\">T<\/span><\/label>\n <div class=\"ssc-input-row\">\n <input type=\"number\" id=\"torque\" name=\"torque\" step=\"any\" min=\"0\" placeholder=\"e.g. 800\" class=\"ssc-num-input\" \/>\n <select id=\"torqueUnit\" class=\"ssc-unit-select\">\n <option value=\"Nm\">N\u00b7m<\/option>\n <option value=\"lbin\">lb\u00b7in<\/option>\n <\/select>\n <\/div>\n <\/div>\n <\/div>\n\n <div>\n <label for=\"material\" class=\"ssc-label\">Material library \u2014 allowable shear stress <span class=\"ssc-mono\">[\u03c4]<\/span><\/label>\n <select id=\"material\" class=\"ssc-field-select\">\n <option value=\"custom\">Custom value (manual entry below)<\/option>\n <option value=\"45\" data-mpa=\"40\" data-note=\"45# steel, normalized \/ typical shaft\">45# steel (normalized) \u2014 40 MPa<\/option>\n <option value=\"40cr\" data-mpa=\"55\" data-note=\"40Cr alloy, Q&T \u2014 indicative\">40Cr (quenched & tempered) \u2014 55 MPa<\/option>\n <option value=\"304\" data-mpa=\"35\" data-note=\"AISI 304 \u2014 conservative\">304 stainless steel \u2014 35 MPa<\/option>\n <option value=\"316\" data-mpa=\"38\" data-note=\"AISI 316\">316 stainless steel \u2014 38 MPa<\/option>\n <option value=\"q235\" data-mpa=\"32\" data-note=\"Q235 structural \u2014 conservative\">Q235 \u2014 32 MPa<\/option>\n <option value=\"6061\" data-mpa=\"55\" data-note=\"6061-T6 aluminum \u2014 verify for shafts\">6061-T6 aluminum \u2014 55 MPa<\/option>\n <\/select>\n <p id=\"materialNote\" class=\"ssc-hint ssc-hidden\"><\/p>\n <\/div>\n\n <div class=\"ssc-grid-2\">\n <div>\n <label for=\"tau\" class=\"ssc-label\">Allowable shear stress <span class=\"ssc-mono\">[\u03c4]<\/span><\/label>\n <div class=\"ssc-input-row\">\n <input type=\"number\" id=\"tau\" name=\"tau\" step=\"any\" min=\"0\" placeholder=\"40\" class=\"ssc-num-input\" \/>\n <select id=\"tauUnit\" class=\"ssc-unit-select\">\n <option value=\"MPa\">MPa<\/option>\n <option value=\"psi\">psi<\/option>\n <\/select>\n <\/div>\n <\/div>\n <div>\n <label for=\"safety\" class=\"ssc-label\">Safety factor <span class=\"ssc-mono\">S<\/span><\/label>\n <input type=\"number\" id=\"safety\" name=\"safety\" step=\"any\" min=\"0.1\" value=\"1.5\" class=\"ssc-field-input\" \/>\n <p class=\"ssc-hint\">Uses design stress <span class=\"ssc-mono\">[\u03c4]\/S<\/span> (larger S \u2192 larger d).<\/p>\n <\/div>\n <\/div>\n\n <div class=\"ssc-btn-wrap\">\n <button type=\"submit\" class=\"ssc-calc-btn\">Calculate<\/button>\n <\/div>\n <\/form>\n\n <div id=\"resultPanel\" class=\"ssc-results ssc-hidden\">\n <h3 class=\"ssc-results-title\">Detailed results<\/h3>\n <dl class=\"ssc-dl\">\n <div class=\"ssc-result-row\">\n <dt>Equivalent torque <span style=\"color: #1e40af\">T<sub>e<\/sub><\/span><\/dt>\n <dd id=\"outTe\" class=\"ssc-dd-strong\"><\/dd>\n <\/div>\n <div class=\"ssc-result-row\">\n <dt>Design allowable shear <span style=\"color: #1e40af\">[\u03c4]\/S<\/span><\/dt>\n <dd id=\"outTauDesign\"><\/dd>\n <\/div>\n <div class=\"ssc-result-row\">\n <dt>Minimum required diameter <span style=\"color: #1e40af\">d<\/span><\/dt>\n <dd id=\"outD\" class=\"ssc-dd-blue\"><\/dd>\n <\/div>\n <\/dl>\n <p id=\"formulaNote\" class=\"ssc-formula-note\"><\/p>\n <\/div>\n\n <div id=\"errorBox\" class=\"ssc-error ssc-hidden\"><\/div>\n <\/section>\n <\/div>\n\n <script>\n (function () {\n const Nm_PER_lbin = 0.112984829;\n const PSI_PER_MPA = 145.0377377;\n\n const el = (id) => document.getElementById(id);\n\n function toNm(value, unit) {\n if (unit === 'lbin') return value * Nm_PER_lbin;\n return value;\n }\n\n function toPa(value, unit) {\n if (unit === 'psi') return value * 6894.757293168;\n return value * 1e6;\n }\n\n function formatNum(n, digits) {\n if (!isFinite(n)) return '\u2014';\n const abs = Math.abs(n);\n if (abs >= 1000 || (abs > 0 && abs < 0.01)) return n.toExponential(digits ?? 4);\n return n.toFixed(digits ?? 3).replace(\/\\.?0+$\/, '') || '0';\n }\n\n function compute() {\n const mRaw = parseFloat(el('moment').value);\n const tRaw = parseFloat(el('torque').value);\n const tauRaw = parseFloat(el('tau').value);\n const sRaw = parseFloat(el('safety').value);\n const mUnit = el('momentUnit').value;\n const tUnit = el('torqueUnit').value;\n const tauUnit = el('tauUnit').value;\n\n el('errorBox').classList.add('ssc-hidden');\n el('resultPanel').classList.add('ssc-hidden');\n\n if ([mRaw, tRaw, tauRaw, sRaw].some((v) => Number.isNaN(v))) {\n el('errorBox').textContent = 'Please enter valid numbers for M, T, [\u03c4], and S.';\n el('errorBox').classList.remove('ssc-hidden');\n return;\n }\n if (mRaw < 0 || tRaw < 0 || tauRaw <= 0 || sRaw <= 0) {\n el('errorBox').textContent = 'M and T must be \u2265 0; [\u03c4] and S must be positive.';\n el('errorBox').classList.remove('ssc-hidden');\n return;\n }\n\n const M = toNm(mRaw, mUnit);\n const T = toNm(tRaw, tUnit);\n const tauAllowPa = toPa(tauRaw, tauUnit);\n const S = sRaw;\n const tauDesignPa = tauAllowPa \/ S;\n\n const Te = Math.sqrt(M * M + T * T);\n const dM = Math.pow((16 * Te) \/ (Math.PI * tauDesignPa), 1 \/ 3);\n\n const displayTauUnit = tauUnit;\n const TeLbIn = Te \/ Nm_PER_lbin;\n const dInch = dM \/ 0.0254;\n\n el('outTe').innerHTML =\n formatNum(Te, 4) +\n ' N\u00b7m \u00b7 ' +\n formatNum(TeLbIn, 4) +\n ' lb\u00b7in <span class=\"ssc-te-note\">T<sub>e<\/sub> = \u221a(M\u00b2 + T\u00b2) after converting M and T to SI.<\/span>';\n\n const tauDesignDisplay = tauUnit === 'psi' ? tauDesignPa \/ 6894.757293168 : tauDesignPa \/ 1e6;\n el('outTauDesign').textContent = formatNum(tauDesignDisplay, 4) + ' ' + displayTauUnit;\n\n const imperialPreferred = mUnit === 'lbin' && tUnit === 'lbin';\n el('outD').textContent = imperialPreferred\n ? formatNum(dInch, 4) + ' in \u00b7 ' + formatNum(dM * 1000, 3) + ' mm'\n : formatNum(dM * 1000, 3) + ' mm \u00b7 ' + formatNum(dInch, 4) + ' in';\n\n el('formulaNote').textContent =\n 'Tresca (maximum shear stress): d = \u221b(16\u00b7T_e\u00b7S \/ (\u03c0\u00b7[\u03c4])). Inputs converted to SI for the core calculation; results shown in your selected shaft units where applicable.';\n\n el('resultPanel').classList.remove('ssc-hidden');\n }\n\n el('material').addEventListener('change', function () {\n const opt = this.options[this.selectedIndex];\n const noteEl = el('materialNote');\n if (this.value === 'custom') {\n noteEl.classList.add('ssc-hidden');\n return;\n }\n const mpa = parseFloat(opt.getAttribute('data-mpa'));\n if (!Number.isNaN(mpa)) {\n if (el('tauUnit').value === 'MPa') el('tau').value = String(mpa);\n else el('tau').value = String((mpa * PSI_PER_MPA).toFixed(0));\n }\n const note = opt.getAttribute('data-note');\n if (note) {\n noteEl.textContent = note;\n noteEl.classList.remove('ssc-hidden');\n } else noteEl.classList.add('ssc-hidden');\n });\n\n el('tauUnit').addEventListener('change', function () {\n const tauIn = parseFloat(el('tau').value);\n if (Number.isNaN(tauIn) || tauIn <= 0) return;\n if (this.value === 'psi') el('tau').value = String((tauIn * PSI_PER_MPA).toFixed(2));\n else el('tau').value = String((tauIn \/ PSI_PER_MPA).toFixed(4));\n });\n\n el('calcForm').addEventListener('submit', function (e) {\n e.preventDefault();\n compute();\n });\n })();\n <\/script>\n<\/body>\n<\/html>\n\n","protected":false},"excerpt":{"rendered":"<p>The Shaft Strength & Diameter Calculator is an essential engineering tool designed to help mechanical engineers accurately determine the required shaft diameter based on torque,…<\/p>","protected":false},"author":2,"featured_media":24484,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"pmpro_default_level":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[8520],"tags":[8522,2940,8521],"class_list":["post-24483","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mechanical-basic-component-design","tag-diameter-sizing","tag-shaft-design","tag-strength-calc","pmpro-has-access"],"acf":[],"jetpack_featured_media_url":"https:\/\/www.mechstream.com\/wp-content\/uploads\/2026\/03\/Shaft-Strength-Diameter-Calculator.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts\/24483","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/comments?post=24483"}],"version-history":[{"count":0,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts\/24483\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/media\/24484"}],"wp:attachment":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/media?parent=24483"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/categories?post=24483"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/tags?post=24483"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}