{"id":24551,"date":"2026-07-21T06:16:43","date_gmt":"2026-07-21T06:16:43","guid":{"rendered":"https:\/\/www.mechstream.com\/?p=24551"},"modified":"2026-07-21T06:16:47","modified_gmt":"2026-07-21T06:16:47","slug":"gear-contact-strength-calculator","status":"publish","type":"post","link":"https:\/\/www.mechstream.com\/pt\/gear-contact-strength-calculator\/","title":{"rendered":"Gear Contact Strength Calculator"},"content":{"rendered":"\n

The Gear Contact Strength Calculator<\/strong> is a free online engineering tool that helps engineers and gear designers accurately evaluate the contact stress and surface strength of spur, helical, and other gear types. By entering essential parameters such as transmitted torque, gear module, number of teeth, face width, material properties, and operating conditions, the Gear Contact Strength Calculator<\/strong> quickly calculates gear contact strength to determine whether the design meets industry standards and performance requirements. This calculator helps reduce the risk of surface fatigue, pitting, and premature gear failure while improving transmission efficiency and reliability. Ideal for mechanical engineers, gearbox designers, and manufacturers, it provides fast, accurate, browser-based calculations without requiring specialized software.<\/p>\n\n\n\n\n\n\n \n \n Gear Contact Strength Calculator | Hertzian Contact Stress<\/title>\n <style>\n \/* WordPress-safe: all styles scoped under #gear-hertz-calc \u2014 no global leakage *\/\n #gear-hertz-calc {\n --ghc-bg: #f0f4f8;\n --ghc-surface: #ffffff;\n --ghc-surface-2: #f8fafc;\n --ghc-border: #e2e8f0;\n --ghc-text: #1e293b;\n --ghc-text-muted: #64748b;\n --ghc-accent: #2563eb;\n --ghc-accent-hover: #1d4ed8;\n --ghc-accent-soft: rgba(37, 99, 235, 0.08);\n --ghc-success: #059669;\n --ghc-success-bg: #ecfdf5;\n --ghc-warning: #d97706;\n --ghc-warning-bg: #fffbeb;\n --ghc-danger: #dc2626;\n --ghc-danger-bg: #fef2f2;\n --ghc-shadow: 0 1px 3px rgba(15, 23, 42, 0.06), 0 4px 16px rgba(15, 23, 42, 0.06);\n --ghc-radius: 12px;\n --ghc-radius-sm: 8px;\n --ghc-font: \"Segoe UI\", system-ui, -apple-system, sans-serif;\n --ghc-mono: \"Cascadia Code\", \"Consolas\", monospace;\n\n font-family: var(--ghc-font);\n color: var(--ghc-text);\n line-height: 1.6;\n font-size: 16px;\n isolation: isolate;\n contain: layout style;\n display: block;\n width: 100%;\n max-width: 100%;\n margin: 0;\n padding: 0;\n background: transparent;\n border: none;\n box-sizing: border-box;\n }\n\n #gear-hertz-calc *,\n #gear-hertz-calc *::before,\n #gear-hertz-calc *::after {\n box-sizing: border-box;\n }\n\n #gear-hertz-calc .ghc-container {\n max-width: 720px;\n margin: 0 auto;\n padding: 1.5rem;\n display: flex;\n flex-direction: column;\n gap: 1.5rem;\n }\n\n #gear-hertz-calc .ghc-btn {\n display: inline-flex;\n align-items: center;\n gap: 0.4rem;\n padding: 0.5rem 1rem;\n border: none;\n border-radius: var(--ghc-radius-sm);\n font-size: 0.875rem;\n font-weight: 500;\n cursor: pointer;\n transition: background 0.15s, transform 0.1s;\n font-family: var(--ghc-font);\n line-height: 1.4;\n text-decoration: none;\n appearance: none;\n -webkit-appearance: none;\n background-image: none;\n box-shadow: none;\n margin: 0;\n }\n #gear-hertz-calc .ghc-btn:active { transform: scale(0.97); 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}\n #gear-hertz-calc #ghc-resultsCard.ghc-visible { display: block; }\n\n #gear-hertz-calc .ghc-error-msg {\n color: var(--ghc-danger);\n font-size: 0.8125rem;\n padding: 0.75rem;\n background: var(--ghc-danger-bg);\n border-radius: var(--ghc-radius-sm);\n border: 1px solid var(--ghc-danger);\n margin-bottom: 1rem;\n display: none;\n }\n #gear-hertz-calc .ghc-error-msg.ghc-visible { display: block; }\n <\/style>\n<\/head>\n<body>\n\n<!-- WordPress embed: copy everything from #gear-hertz-calc through its closing <\/script> -->\n<div id=\"gear-hertz-calc\">\n<div class=\"ghc-container\">\n\n <div class=\"ghc-card\">\n <div class=\"ghc-card-header\">\n <h2>Input Parameters<\/h2>\n <\/div>\n <div class=\"ghc-card-body\">\n\n <div class=\"ghc-form-section\">\n <div class=\"ghc-section-title\">Load Input<\/div>\n <div class=\"ghc-toggle-group\" id=\"ghc-loadModeToggle\">\n <button type=\"button\" class=\"ghc-toggle-btn ghc-active\" data-mode=\"torque\">Torque T\u2081<\/button>\n <button type=\"button\" class=\"ghc-toggle-btn\" data-mode=\"power\">Power P + Speed n\u2081<\/button>\n <\/div>\n\n <div id=\"ghc-torqueGroup\">\n <div class=\"ghc-form-group\">\n <label>\n T\u2081 Pinion Torque\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Torque transmitted by the pinion (driving gear), in N\u00b7m. Used to calculate tangential force F\u209c = 2000\u00b7T\u2081\/d\u2081\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-torque\" value=\"500\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">N\u00b7m<\/span>\n <\/div>\n <\/div>\n <\/div>\n\n <div id=\"ghc-powerGroup\" class=\"ghc-hidden\">\n <div class=\"ghc-form-row\">\n <div class=\"ghc-form-group\">\n <label>\n P Transmitted Power\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Input power in kW. T\u2081 = 9550\u00b7P\/n\u2081 (N\u00b7m)\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-power\" value=\"50\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">kW<\/span>\n <\/div>\n <\/div>\n <div class=\"ghc-form-group\">\n <label>\n n\u2081 Pinion Speed\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Pinion rotational speed in r\/min (rpm)\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-speed\" value=\"1500\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">rpm<\/span>\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n\n <div class=\"ghc-form-section\">\n <div class=\"ghc-section-title\">Geometry<\/div>\n <div class=\"ghc-toggle-group\" id=\"ghc-geoModeToggle\">\n <button type=\"button\" class=\"ghc-toggle-btn ghc-active\" data-mode=\"diameter\">Pitch Diameter d\u2081<\/button>\n <button type=\"button\" class=\"ghc-toggle-btn\" data-mode=\"module\">Module m + Teeth z\u2081<\/button>\n <\/div>\n\n <div id=\"ghc-diameterGroup\">\n <div class=\"ghc-form-group\">\n <label>\n d\u2081 Pinion Pitch Diameter\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Pinion pitch circle diameter in mm. Typical range depends on module and number of teeth.\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-d1\" value=\"100\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">mm<\/span>\n <\/div>\n <\/div>\n <\/div>\n\n <div id=\"ghc-moduleGroup\" class=\"ghc-hidden\">\n <div class=\"ghc-form-row\">\n <div class=\"ghc-form-group\">\n <label>\n m Module\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Gear module in mm. d\u2081 = m\u00b7z\u2081\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-module\" value=\"3\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">mm<\/span>\n <\/div>\n <\/div>\n <div class=\"ghc-form-group\">\n <label>\n z\u2081 Pinion Teeth\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Number of pinion teeth. Typically \u2265 17 to avoid undercutting.\" tabindex=\"0\">?<\/span>\n <\/label>\n <input type=\"number\" id=\"ghc-z1\" value=\"30\" min=\"1\" step=\"1\">\n <\/div>\n <\/div>\n <\/div>\n\n <div class=\"ghc-toggle-group\" id=\"ghc-ratioModeToggle\" style=\"margin-top:0.5rem\">\n <button type=\"button\" class=\"ghc-toggle-btn ghc-active\" data-mode=\"ratio\">Gear Ratio u<\/button>\n <button type=\"button\" class=\"ghc-toggle-btn\" data-mode=\"z2\">Gear Teeth z\u2082<\/button>\n <\/div>\n\n <div id=\"ghc-ratioGroup\">\n <div class=\"ghc-form-group\">\n <label>\n u Gear Ratio\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Gear ratio u = z\u2082\/z\u2081 = n\u2081\/n\u2082 = d\u2082\/d\u2081\" tabindex=\"0\">?<\/span>\n <\/label>\n <input type=\"number\" id=\"ghc-ratio\" value=\"3\" min=\"0\" step=\"any\">\n <\/div>\n <\/div>\n <div id=\"ghc-z2Group\" class=\"ghc-hidden\">\n <div class=\"ghc-form-group\">\n <label>\n z\u2082 Gear Teeth\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Number of gear (wheel) teeth. u = z\u2082\/z\u2081\" tabindex=\"0\">?<\/span>\n <\/label>\n <input type=\"number\" id=\"ghc-z2\" value=\"90\" min=\"1\" step=\"1\">\n <\/div>\n <\/div>\n\n <div class=\"ghc-form-group\">\n <label>\n b Face Width\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Gear face width in mm. Typically b = (8\u201315)\u00b7m\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-faceWidth\" value=\"30\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">mm<\/span>\n <\/div>\n <\/div>\n\n <div class=\"ghc-form-group\">\n <label>\n \u03b1 Transverse Pressure Angle\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Standard pressure angle, typically 20\u00b0 (also 14.5\u00b0 or 25\u00b0)\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-pressureAngle\" value=\"20\" min=\"0\" max=\"45\" step=\"any\">\n <span class=\"ghc-unit\">\u00b0<\/span>\n <\/div>\n <\/div>\n <\/div>\n\n <div class=\"ghc-form-section\">\n <div class=\"ghc-section-title\">Material Properties<\/div>\n <div class=\"ghc-form-group\">\n <label>\n Material Pair Preset\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Select a common material pairing to auto-fill Young's modulus and Poisson's ratio\" tabindex=\"0\">?<\/span>\n <\/label>\n <select id=\"ghc-materialPreset\">\n <option value=\"steel_steel\">Steel vs. Steel<\/option>\n <option value=\"ci_steel\">Cast Iron vs. Steel<\/option>\n <option value=\"bronze_steel\">Bronze vs. Steel<\/option>\n <option value=\"custom\">Custom<\/option>\n <\/select>\n <\/div>\n <div class=\"ghc-form-row\">\n <div class=\"ghc-form-group\">\n <label>\n E\u2081 Pinion Young’s Modulus\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Young's modulus of pinion material in MPa. Steel \u2248 206,000 MPa\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-E1\" value=\"206000\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">MPa<\/span>\n <\/div>\n <\/div>\n <div class=\"ghc-form-group\">\n <label>\n E\u2082 Gear Young’s Modulus\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Young's modulus of gear material in MPa\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-E2\" value=\"206000\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">MPa<\/span>\n <\/div>\n <\/div>\n <\/div>\n <div class=\"ghc-form-row\">\n <div class=\"ghc-form-group\">\n <label>\n \u03bd\u2081 Pinion Poisson’s Ratio\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Poisson's ratio of pinion material. Steel \u2248 0.3\" tabindex=\"0\">?<\/span>\n <\/label>\n <input type=\"number\" id=\"ghc-nu1\" value=\"0.3\" min=\"0\" max=\"0.5\" step=\"any\">\n <\/div>\n <div class=\"ghc-form-group\">\n <label>\n \u03bd\u2082 Gear Poisson’s Ratio\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Poisson's ratio of gear material\" tabindex=\"0\">?<\/span>\n <\/label>\n <input type=\"number\" id=\"ghc-nu2\" value=\"0.3\" min=\"0\" max=\"0.5\" step=\"any\">\n <\/div>\n <\/div>\n <\/div>\n\n <div class=\"ghc-form-section\">\n <div class=\"ghc-section-title\">Factors<\/div>\n <div class=\"ghc-form-group\">\n <label>\n K_A Application Factor\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Application\/overload factor accounting for startup shocks, vibration, etc. Uniform load: 1.0\u20131.25, moderate shock: 1.25\u20131.75, heavy shock: 1.75\u20132.25\" tabindex=\"0\">?<\/span>\n <\/label>\n <input type=\"number\" id=\"ghc-KA\" value=\"1.25\" min=\"0\" step=\"any\">\n <\/div>\n <div class=\"ghc-form-group\">\n <label>\n \u03c3_H,lim Allowable Contact Stress\n <span class=\"ghc-tooltip-trigger\" data-tip=\"Allowable Hertzian contact stress limit in MPa. Typical value for hardened gear steel \u2248 1500 MPa\" tabindex=\"0\">?<\/span>\n <\/label>\n <div class=\"ghc-input-unit\">\n <input type=\"number\" id=\"ghc-allowableStress\" value=\"1500\" min=\"0\" step=\"any\">\n <span class=\"ghc-unit\">MPa<\/span>\n <\/div>\n <\/div>\n <\/div>\n\n <div class=\"ghc-calculate-bar\">\n <button type=\"button\" class=\"ghc-btn ghc-btn-primary\" id=\"ghc-calculateBtn\">Calculate<\/button>\n <\/div>\n <\/div>\n <\/div>\n\n <div class=\"ghc-card\" id=\"ghc-resultsCard\">\n <div class=\"ghc-card-header\">\n <h2>Results<\/h2>\n <\/div>\n <div class=\"ghc-card-body\">\n <div class=\"ghc-error-msg\" id=\"ghc-errorMsg\"><\/div>\n\n <div class=\"ghc-result-hero\">\n <div class=\"ghc-label\">Maximum Hertzian Contact Stress \u03c3_H<\/div>\n <div>\n <span class=\"ghc-value\" id=\"ghc-sigmaH\">\u2014<\/span>\n <span class=\"ghc-unit\"> MPa<\/span>\n <\/div>\n <div class=\"ghc-safety-badge ghc-pass\" id=\"ghc-safetyBadge\">\n <span class=\"ghc-dot\"><\/span>\n <span id=\"ghc-safetyText\">\u2014<\/span>\n <\/div>\n <\/div>\n\n <table class=\"ghc-breakdown\">\n <tbody>\n <tr>\n <td><span class=\"ghc-symbol\">F<\/span><sub>t<\/sub> Tangential Force<\/td>\n <td id=\"ghc-Ft\">\u2014 N<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">F<\/span><sub>N<\/sub> Normal Force<\/td>\n <td id=\"ghc-FN\">\u2014 N<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">T<\/span><sub>1<\/sub> Input Torque<\/td>\n <td id=\"ghc-T1out\">\u2014 N\u00b7m<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">d<\/span><sub>1<\/sub> Pinion Pitch Diameter<\/td>\n <td id=\"ghc-d1out\">\u2014 mm<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">d<\/span><sub>2<\/sub> Gear Pitch Diameter<\/td>\n <td id=\"ghc-d2out\">\u2014 mm<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">u<\/span> Gear Ratio<\/td>\n <td id=\"ghc-uout\">\u2014<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">v<\/span> Pitch Line Velocity<\/td>\n <td id=\"ghc-velocity\">\u2014 m\/s<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">\u03c1<\/span><sub>1<\/sub> Pinion Radius of Curvature<\/td>\n <td id=\"ghc-rho1\">\u2014 mm<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">\u03c1<\/span><sub>2<\/sub> Gear Radius of Curvature<\/td>\n <td id=\"ghc-rho2\">\u2014 mm<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">\u03c1<\/span><sub>e<\/sub> Equivalent Radius of Curvature<\/td>\n <td id=\"ghc-rhoe\">\u2014 mm<\/td>\n <\/tr>\n <tr>\n <td><span class=\"ghc-symbol\">E<\/span><sub>e<\/sub> Equivalent Elastic Modulus<\/td>\n <td id=\"ghc-Ee\">\u2014 MPa<\/td>\n <\/tr>\n <tr>\n <td>Contact Stress Utilization<\/td>\n <td id=\"ghc-utilization\">\u2014 %<\/td>\n <\/tr>\n <\/tbody>\n <\/table>\n\n <div class=\"ghc-formula-box\">\n <h3>Core Formulas<\/h3>\n <div class=\"ghc-formula\">\n F<sub>t<\/sub> = 2000 \u00b7 T<sub>1<\/sub> \/ d<sub>1<\/sub><br>\n F<sub>N<\/sub> = F<sub>t<\/sub> \/ cos \u03b1<br>\n \u03c1<sub>1<\/sub> = d<sub>1<\/sub> \u00b7 sin \u03b1 \/ 2<br>\n \u03c1<sub>2<\/sub> = d<sub>2<\/sub> \u00b7 sin \u03b1 \/ 2<br>\n 1\/\u03c1<sub>e<\/sub> = 1\/\u03c1<sub>1<\/sub> + 1\/\u03c1<sub>2<\/sub><br>\n \u03c3<sub>H<\/sub> = \u221a[ F<sub>N<\/sub> \u00b7 K<sub>A<\/sub> \/ (\u03c0 \u00b7 b \u00b7 \u03c1<sub>e<\/sub> \u00b7 ((1\u2212\u03bd\u2081\u00b2)\/E\u2081 + (1\u2212\u03bd\u2082\u00b2)\/E\u2082)) ]\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n\n<\/div>\n<\/div>\n\n<script>\n(function () {\n 'use strict';\n\n var root = document.getElementById('gear-hertz-calc');\n if (!root) return;\n\n var MATERIALS = {\n steel_steel: { E1: 206000, E2: 206000, nu1: 0.30, nu2: 0.30 },\n ci_steel: { E1: 170000, E2: 206000, nu1: 0.26, nu2: 0.30 },\n bronze_steel: { E1: 100000, E2: 206000, nu1: 0.35, nu2: 0.30 },\n };\n\n function $(id) { return root.querySelector('#' + id); }\n\n var loadMode = 'torque';\n var geoMode = 'diameter';\n var ratioMode = 'ratio';\n\n function setupToggle(groupId, callback) {\n var group = $(groupId);\n if (!group) return;\n group.querySelectorAll('.ghc-toggle-btn').forEach(function (btn) {\n btn.addEventListener('click', function () {\n group.querySelectorAll('.ghc-toggle-btn').forEach(function (b) {\n b.classList.remove('ghc-active');\n });\n btn.classList.add('ghc-active');\n callback(btn.dataset.mode);\n });\n });\n }\n\n setupToggle('ghc-loadModeToggle', function (mode) {\n loadMode = mode;\n $('ghc-torqueGroup').classList.toggle('ghc-hidden', mode !== 'torque');\n $('ghc-powerGroup').classList.toggle('ghc-hidden', mode !== 'power');\n });\n\n setupToggle('ghc-geoModeToggle', function (mode) {\n geoMode = mode;\n $('ghc-diameterGroup').classList.toggle('ghc-hidden', mode !== 'diameter');\n $('ghc-moduleGroup').classList.toggle('ghc-hidden', mode !== 'module');\n });\n\n setupToggle('ghc-ratioModeToggle', function (mode) {\n ratioMode = mode;\n $('ghc-ratioGroup').classList.toggle('ghc-hidden', mode !== 'ratio');\n $('ghc-z2Group').classList.toggle('ghc-hidden', mode !== 'z2');\n });\n\n $('ghc-materialPreset').addEventListener('change', function (e) {\n var preset = MATERIALS[e.target.value];\n if (preset) {\n $('ghc-E1').value = preset.E1;\n $('ghc-E2').value = preset.E2;\n $('ghc-nu1').value = preset.nu1;\n $('ghc-nu2').value = preset.nu2;\n }\n });\n\n ['ghc-E1', 'ghc-E2', 'ghc-nu1', 'ghc-nu2'].forEach(function (id) {\n $(id).addEventListener('input', function () {\n $('ghc-materialPreset').value = 'custom';\n });\n });\n\n $('ghc-calculateBtn').addEventListener('click', function () {\n calculate();\n $('ghc-resultsCard').classList.add('ghc-visible');\n $('ghc-resultsCard').scrollIntoView({ behavior: 'smooth', block: 'start' });\n });\n\n function fmt(val, decimals) {\n if (decimals === undefined) decimals = 2;\n if (val === null || val === undefined || isNaN(val)) return '\u2014';\n return val.toLocaleString('en-US', {\n minimumFractionDigits: decimals,\n maximumFractionDigits: decimals,\n });\n }\n\n function calculate() {\n var errEl = $('ghc-errorMsg');\n errEl.classList.remove('ghc-visible');\n errEl.textContent = '';\n\n try {\n var alphaDeg = parseFloat($('ghc-pressureAngle').value);\n var b = parseFloat($('ghc-faceWidth').value);\n var E1 = parseFloat($('ghc-E1').value);\n var E2 = parseFloat($('ghc-E2').value);\n var nu1 = parseFloat($('ghc-nu1').value);\n var nu2 = parseFloat($('ghc-nu2').value);\n var KA = parseFloat($('ghc-KA').value);\n var sigmaLim = parseFloat($('ghc-allowableStress').value);\n var n1 = parseFloat($('ghc-speed').value) || 0;\n\n var d1;\n if (geoMode === 'diameter') {\n d1 = parseFloat($('ghc-d1').value);\n } else {\n d1 = parseFloat($('ghc-module').value) * parseFloat($('ghc-z1').value);\n }\n\n var u;\n if (ratioMode === 'ratio') {\n u = parseFloat($('ghc-ratio').value);\n } else {\n var z1g = geoMode === 'module' ? parseFloat($('ghc-z1').value) : null;\n var z2 = parseFloat($('ghc-z2').value);\n if (geoMode === 'module' && z1g > 0) {\n u = z2 \/ z1g;\n } else {\n u = z2 \/ (parseFloat($('ghc-z1').value) || 1);\n }\n }\n\n var d2 = d1 * u;\n\n var T1;\n if (loadMode === 'torque') {\n T1 = parseFloat($('ghc-torque').value);\n } else {\n T1 = (9550 * parseFloat($('ghc-power').value)) \/ parseFloat($('ghc-speed').value);\n }\n\n var checks = [\n [d1 > 0, 'Pitch diameter d\u2081 must be greater than 0'],\n [u > 0, 'Gear ratio u must be greater than 0'],\n [b > 0, 'Face width b must be greater than 0'],\n [T1 > 0, 'Torque T\u2081 must be greater than 0'],\n [alphaDeg > 0 && alphaDeg < 45, 'Pressure angle \u03b1 must be between 0\u00b0 and 45\u00b0'],\n [E1 > 0 && E2 > 0, 'Young\\'s modulus E must be greater than 0'],\n [KA > 0, 'Application factor K_A must be greater than 0'],\n ];\n for (var i = 0; i < checks.length; i++) {\n if (!checks[i][0]) throw new Error(checks[i][1]);\n }\n\n var alpha = alphaDeg * Math.PI \/ 180;\n var Ft = (2000 * T1) \/ d1;\n var FN = Ft \/ Math.cos(alpha);\n var rho1 = (d1 * Math.sin(alpha)) \/ 2;\n var rho2 = (d2 * Math.sin(alpha)) \/ 2;\n var rhoE = 1 \/ (1 \/ rho1 + 1 \/ rho2);\n var compliance = (1 - nu1 * nu1) \/ E1 + (1 - nu2 * nu2) \/ E2;\n var Ee = 1 \/ compliance;\n var sigmaH = Math.sqrt((FN * KA) \/ (Math.PI * b * rhoE * compliance));\n var v = (Math.PI * d1 * n1) \/ 60000;\n var vDisplay = loadMode === 'power' ? v : (n1 > 0 ? v : null);\n\n var utilization = (sigmaH \/ sigmaLim) * 100;\n var badge = $('ghc-safetyBadge');\n var safetyText = $('ghc-safetyText');\n\n badge.classList.remove('ghc-pass', 'ghc-warning', 'ghc-fail');\n if (sigmaH <= sigmaLim * 0.85) {\n badge.classList.add('ghc-pass');\n safetyText.textContent = 'PASS \u2014 Stress utilization ' + fmt(utilization, 1) + '%';\n } else if (sigmaH <= sigmaLim) {\n badge.classList.add('ghc-warning');\n safetyText.textContent = 'WARNING \u2014 Approaching allowable limit (' + fmt(utilization, 1) + '%)';\n } else {\n badge.classList.add('ghc-fail');\n safetyText.textContent = 'FAIL \u2014 Exceeds allowable limit (' + fmt(utilization, 1) + '%)';\n }\n\n $('ghc-sigmaH').textContent = fmt(sigmaH);\n $('ghc-Ft').textContent = fmt(Ft) + ' N';\n $('ghc-FN').textContent = fmt(FN) + ' N';\n $('ghc-T1out').textContent = fmt(T1) + ' N\u00b7m';\n $('ghc-d1out').textContent = fmt(d1) + ' mm';\n $('ghc-d2out').textContent = fmt(d2) + ' mm';\n $('ghc-uout').textContent = fmt(u, 3);\n $('ghc-velocity').textContent = vDisplay !== null ? fmt(vDisplay, 3) + ' m\/s' : '\u2014 m\/s';\n $('ghc-rho1').textContent = fmt(rho1, 3) + ' mm';\n $('ghc-rho2').textContent = fmt(rho2, 3) + ' mm';\n $('ghc-rhoe').textContent = fmt(rhoE, 3) + ' mm';\n $('ghc-Ee').textContent = fmt(Ee, 0) + ' MPa';\n $('ghc-utilization').textContent = fmt(utilization, 1) + ' %';\n\n } catch (err) {\n errEl.textContent = err.message;\n errEl.classList.add('ghc-visible');\n $('ghc-sigmaH').textContent = '\u2014';\n $('ghc-safetyText').textContent = 'Invalid input';\n $('ghc-safetyBadge').classList.remove('ghc-pass', 'ghc-warning', 'ghc-fail');\n }\n }\n})();\n<\/script>\n\n<\/body>\n<\/html>\n\n","protected":false},"excerpt":{"rendered":"<p>The Gear Contact Strength Calculator is a free online engineering tool that helps engineers and gear designers accurately evaluate the contact stress and surface strength…<\/p>","protected":false},"author":2,"featured_media":24552,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"pmpro_default_level":"","_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[8520],"tags":[8543,3673,3560,8542],"class_list":["post-24551","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mechanical-basic-component-design","tag-contact-stress","tag-gear-calculator","tag-gear-design","tag-gear-strength","pmpro-has-access"],"acf":[],"jetpack_featured_media_url":"https:\/\/www.mechstream.com\/wp-content\/uploads\/2026\/07\/Gear-Contact-Strength-Calculator.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts\/24551","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=24551"}],"version-history":[{"count":1,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts\/24551\/revisions"}],"predecessor-version":[{"id":24553,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/posts\/24551\/revisions\/24553"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/media\/24552"}],"wp:attachment":[{"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/media?parent=24551"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/categories?post=24551"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mechstream.com\/pt\/wp-json\/wp\/v2\/tags?post=24551"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}