Critical Speed Calculator<\/title>\n <style>\n .scsc-wrap,\n .scsc-wrap *,\n .scsc-wrap *::before,\n .scsc-wrap *::after {\n box-sizing: border-box;\n }\n\n .scsc-wrap {\n --scsc-bg: #f4f6f9;\n --scsc-surface: #ffffff;\n --scsc-border: #d8dee8;\n --scsc-text: #1a2332;\n --scsc-text-muted: #5a6a7e;\n --scsc-accent: #1e5a9e;\n --scsc-accent-light: #e8f0fa;\n --scsc-accent-hover: #164a82;\n --scsc-radius: 10px;\n --scsc-shadow: 0 2px 12px rgba(26, 35, 50, 0.08);\n\n font-family: system-ui, -apple-system, \"Segoe UI\", Roboto, \"Helvetica Neue\", Arial, sans-serif;\n color: var(--scsc-text);\n line-height: 1.5;\n background: var(--scsc-bg);\n border-radius: var(--scsc-radius);\n margin: 1rem 0;\n }\n\n .scsc-wrap .scsc-container {\n max-width: 960px;\n margin: 0 auto;\n padding: 2rem 1.25rem 3rem;\n }\n\n .scsc-wrap .scsc-card {\n background: var(--scsc-surface);\n border: 1px solid var(--scsc-border);\n border-radius: var(--scsc-radius);\n box-shadow: var(--scsc-shadow);\n padding: 1.5rem;\n margin-bottom: 1.25rem;\n }\n\n .scsc-wrap .scsc-card h2 {\n font-size: 1rem;\n font-weight: 600;\n color: var(--scsc-accent);\n margin: 0 0 1.25rem;\n padding-bottom: 0.5rem;\n border-bottom: 2px solid var(--scsc-accent-light);\n }\n\n .scsc-wrap .scsc-form-grid {\n display: grid;\n grid-template-columns: 1fr;\n gap: 1.25rem;\n }\n\n @media (min-width: 640px) {\n .scsc-wrap .scsc-form-grid { grid-template-columns: 1fr 1fr; }\n .scsc-wrap .scsc-form-grid .scsc-full-width { grid-column: 1 \/ -1; }\n }\n\n .scsc-wrap .scsc-field > label {\n display: block;\n font-size: 0.85rem;\n font-weight: 600;\n margin-bottom: 0.4rem;\n color: var(--scsc-text);\n }\n\n .scsc-wrap .scsc-unit {\n font-weight: 400;\n color: var(--scsc-text-muted);\n }\n\n .scsc-wrap .scsc-slider-row {\n display: flex;\n align-items: center;\n gap: 0.75rem;\n }\n\n .scsc-wrap .scsc-slider-row input[type=\"range\"] {\n flex: 1;\n accent-color: var(--scsc-accent);\n height: 6px;\n margin: 0;\n }\n\n .scsc-wrap .scsc-slider-row input[type=\"number\"] {\n width: 5.5rem;\n padding: 0.4rem 0.5rem;\n border: 1px solid var(--scsc-border);\n border-radius: 6px;\n font-size: 0.9rem;\n text-align: right;\n background: var(--scsc-surface);\n color: var(--scsc-text);\n margin: 0;\n }\n\n .scsc-wrap select,\n .scsc-wrap .scsc-custom-input {\n width: 100%;\n padding: 0.45rem 0.6rem;\n border: 1px solid var(--scsc-border);\n border-radius: 6px;\n font-size: 0.9rem;\n background: var(--scsc-surface);\n color: var(--scsc-text);\n margin: 0;\n }\n\n .scsc-wrap .scsc-custom-input { margin-top: 0.5rem; }\n\n .scsc-wrap .scsc-toggle-row {\n display: flex;\n align-items: center;\n gap: 0.75rem;\n margin-bottom: 0.75rem;\n }\n\n .scsc-wrap .scsc-toggle {\n position: relative;\n width: 44px;\n height: 24px;\n flex-shrink: 0;\n margin: 0;\n }\n\n .scsc-wrap .scsc-toggle input {\n opacity: 0;\n width: 0;\n height: 0;\n margin: 0;\n padding: 0;\n }\n\n .scsc-wrap .scsc-toggle-slider {\n position: absolute;\n inset: 0;\n background: #c5cdd8;\n border-radius: 24px;\n cursor: pointer;\n transition: background 0.2s;\n }\n\n .scsc-wrap .scsc-toggle-slider::before {\n content: \"\";\n position: absolute;\n width: 18px;\n height: 18px;\n left: 3px;\n bottom: 3px;\n background: white;\n border-radius: 50%;\n transition: transform 0.2s;\n box-shadow: 0 1px 3px rgba(0,0,0,0.2);\n }\n\n .scsc-wrap .scsc-toggle input:checked + .scsc-toggle-slider { background: var(--scsc-accent); }\n .scsc-wrap .scsc-toggle input:checked + .scsc-toggle-slider::before { transform: translateX(20px); }\n\n .scsc-wrap .scsc-toggle-label {\n font-size: 0.85rem;\n font-weight: 600;\n }\n\n .scsc-wrap .scsc-mass-field { opacity: 0.45; pointer-events: none; transition: opacity 0.2s; }\n .scsc-wrap .scsc-mass-field.scsc-enabled { opacity: 1; pointer-events: auto; }\n\n .scsc-wrap .scsc-btn-calculate {\n display: block;\n width: 33.333%;\n margin: 1.5rem auto 0;\n padding: 0.7rem 1.5rem;\n background: var(--scsc-accent) !important;\n color: #ffffff !important;\n border: none !important;\n border-radius: 8px;\n font-size: 1rem;\n font-weight: 600;\n cursor: pointer;\n letter-spacing: 0.01em;\n transition: background 0.18s, box-shadow 0.18s;\n box-shadow: 0 2px 8px rgba(30,90,158,0.18);\n text-decoration: none !important;\n }\n\n .scsc-wrap .scsc-btn-calculate:hover,\n .scsc-wrap .scsc-btn-calculate:focus,\n .scsc-wrap .scsc-btn-calculate:active {\n background: var(--scsc-accent-hover) !important;\n color: #ffffff !important;\n box-shadow: 0 4px 14px rgba(30,90,158,0.28);\n }\n\n .scsc-wrap .scsc-results-card[hidden] { display: none !important; }\n .scsc-wrap .scsc-results-card:not([hidden]) { display: block !important; }\n\n .scsc-wrap .scsc-results-primary {\n text-align: center;\n padding: 1.5rem 1rem;\n background: linear-gradient(135deg, var(--scsc-accent-light), #f0f5fc);\n border-radius: var(--scsc-radius);\n margin-bottom: 1.25rem;\n }\n\n .scsc-wrap .scsc-results-primary .scsc-value {\n font-size: 2.75rem;\n font-weight: 700;\n color: var(--scsc-accent);\n line-height: 1.1;\n font-variant-numeric: tabular-nums;\n margin: 0;\n }\n\n .scsc-wrap .scsc-results-primary .scsc-result-label {\n font-size: 0.9rem;\n color: var(--scsc-text-muted);\n margin-top: 0.25rem;\n font-weight: 500;\n }\n\n .scsc-wrap .scsc-results-grid {\n display: grid;\n grid-template-columns: repeat(2, 1fr);\n gap: 0.75rem;\n }\n\n @media (min-width: 480px) {\n .scsc-wrap .scsc-results-grid { grid-template-columns: repeat(4, 1fr); }\n }\n\n .scsc-wrap .scsc-result-item {\n background: var(--scsc-bg);\n border-radius: 8px;\n padding: 0.75rem;\n text-align: center;\n }\n\n .scsc-wrap .scsc-result-item .scsc-val {\n font-size: 1.1rem;\n font-weight: 600;\n font-variant-numeric: tabular-nums;\n color: var(--scsc-text);\n margin: 0;\n }\n\n .scsc-wrap .scsc-result-item .scsc-lbl {\n font-size: 0.72rem;\n color: var(--scsc-text-muted);\n margin-top: 0.15rem;\n }\n <\/style>\n<\/head>\n<body>\n \n <div class=\"scsc-wrap\" data-scsc=\"root\">\n <div class=\"scsc-container\">\n <section class=\"scsc-card\">\n <h2>Shaft Parameters<\/h2>\n <div class=\"scsc-form-grid\">\n <div class=\"scsc-field\">\n <label>Shaft Diameter <span class=\"scsc-unit\">(d, mm)<\/span><\/label>\n <div class=\"scsc-slider-row\">\n <input type=\"range\" data-scsc=\"diameter-slider\" min=\"10\" max=\"500\" step=\"1\" value=\"50\">\n <input type=\"number\" data-scsc=\"diameter-input\" min=\"10\" max=\"500\" step=\"1\" value=\"50\">\n <\/div>\n <\/div>\n\n <div class=\"scsc-field\">\n <label>Shaft Length <span class=\"scsc-unit\">(L, mm)<\/span><\/label>\n <div class=\"scsc-slider-row\">\n <input type=\"range\" data-scsc=\"length-slider\" min=\"100\" max=\"5000\" step=\"10\" value=\"1000\">\n <input type=\"number\" data-scsc=\"length-input\" min=\"100\" max=\"5000\" step=\"10\" value=\"1000\">\n <\/div>\n <\/div>\n\n <div class=\"scsc-field\">\n <label>Elastic Modulus <span class=\"scsc-unit\">(E)<\/span><\/label>\n <select data-scsc=\"material-e\">\n <option value=\"200\" data-rho=\"7850\" selected>Steel – 200 GPa<\/option>\n <option value=\"70\" data-rho=\"2700\">Aluminum – 70 GPa<\/option>\n <option value=\"110\" data-rho=\"4500\">Titanium – 110 GPa<\/option>\n <option value=\"100\" data-rho=\"8500\">Bronze\/Brass – 100 GPa<\/option>\n <\/select>\n <\/div>\n\n <div class=\"scsc-field\">\n <label>Material Density <span class=\"scsc-unit\">(rho, kg\/m3)<\/span><\/label>\n <select data-scsc=\"material-rho\">\n <option value=\"7850\" selected>Steel – 7850 kg\/m3<\/option>\n <option value=\"2700\">Aluminum – 2700 kg\/m3<\/option>\n <option value=\"4500\">Titanium – 4500 kg\/m3<\/option>\n <option value=\"8500\">Bronze\/Brass – 8500 kg\/m3<\/option>\n <\/select>\n <\/div>\n\n <div class=\"scsc-field scsc-full-width\">\n <label>Support \/ Boundary Conditions<\/label>\n <select data-scsc=\"boundary\">\n <option value=\"simply-supported\" selected>Simply Supported – Bearings at both ends (Pinned-Pinned)<\/option>\n <option value=\"cantilever\">Cantilever – Overhung shaft (Fixed-Free)<\/option>\n <option value=\"fixed-fixed\">Fixed-Fixed – Rigid bearings at both ends<\/option>\n <\/select>\n <\/div>\n\n <div class=\"scsc-field scsc-full-width\">\n <div class=\"scsc-toggle-row\">\n <label class=\"scsc-toggle\">\n <input type=\"checkbox\" data-scsc=\"mass-toggle\">\n <span class=\"scsc-toggle-slider\"><\/span>\n <\/label>\n <span class=\"scsc-toggle-label\">Add Central Concentrated Mass (Rotor\/Disc)<\/span>\n <\/div>\n <div class=\"scsc-mass-field\" data-scsc=\"mass-field\">\n <label>Concentrated Mass <span class=\"scsc-unit\">(M, kg)<\/span><\/label>\n <div class=\"scsc-slider-row\">\n <input type=\"range\" data-scsc=\"mass-slider\" min=\"0\" max=\"500\" step=\"1\" value=\"10\">\n <input type=\"number\" data-scsc=\"mass-input\" min=\"0\" max=\"500\" step=\"0.1\" value=\"10\">\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n <button type=\"button\" class=\"scsc-btn-calculate\" data-scsc=\"calc-btn\">Calculate<\/button>\n <\/section>\n\n <section class=\"scsc-card scsc-results-card\" data-scsc=\"results-card\" hidden>\n <h2>Results<\/h2>\n <div class=\"scsc-results-primary\">\n <div class=\"scsc-value\" data-scsc=\"critical-rpm\">–<\/div>\n <div class=\"scsc-result-label\">Critical Speed (RPM)<\/div>\n <\/div>\n <div class=\"scsc-results-grid\">\n <div class=\"scsc-result-item\">\n <div class=\"scsc-val\" data-scsc=\"critical-hz\">–<\/div>\n <div class=\"scsc-lbl\">Frequency (Hz)<\/div>\n <\/div>\n <div class=\"scsc-result-item\">\n <div class=\"scsc-val\" data-scsc=\"shaft-mass\">–<\/div>\n <div class=\"scsc-lbl\">Shaft Mass (kg)<\/div>\n <\/div>\n <div class=\"scsc-result-item\">\n <div class=\"scsc-val\" data-scsc=\"inertia\">–<\/div>\n <div class=\"scsc-lbl\">Inertia I (m4)<\/div>\n <\/div>\n <div class=\"scsc-result-item\">\n <div class=\"scsc-val\" data-scsc=\"cross-area\">–<\/div>\n <div class=\"scsc-lbl\">Area A (m2)<\/div>\n <\/div>\n <\/div>\n 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{"id":24509,"date":"2026-07-17T06:30:45","date_gmt":"2026-07-17T06:30:45","guid":{"rendered":"https:\/\/www.mechstream.com\/?p=24509"},"modified":"2026-07-17T07:09:06","modified_gmt":"2026-07-17T07:09:06","slug":"shaft-critical-speed-calculator","status":"publish","type":"post","link":"https:\/\/www.mechstream.com\/fr\/shaft-critical-speed-calculator\/","title":{"rendered":"Shaft Critical Speed Calculator"},"content":{"rendered":"\n

The Shaft Critical Speed Calculator<\/strong> is a free online engineering tool designed to help mechanical engineers, designers, and students accurately calculate the critical speed of rotating shafts. By entering key parameters such as shaft length, diameter, material properties, and support conditions, the calculator quickly determines the shaft’s critical rotational speed, natural frequency, and recommended safe operating speed. Using a Shaft Critical Speed Calculator<\/strong> helps prevent resonance, excessive vibration, and potential mechanical failure, improving equipment reliability and performance. Whether you’re designing transmission systems, rotating machinery, or industrial equipment, this calculator provides fast, accurate, and browser-based calculations with no software installation required.<\/p>\n\n\n\n\n\n\n \n \n Critical Speed Calculator<\/title>\n <style>\n .scsc-wrap,\n .scsc-wrap *,\n .scsc-wrap *::before,\n .scsc-wrap *::after {\n box-sizing: border-box;\n }\n\n .scsc-wrap {\n --scsc-bg: #f4f6f9;\n --scsc-surface: #ffffff;\n --scsc-border: #d8dee8;\n --scsc-text: #1a2332;\n --scsc-text-muted: #5a6a7e;\n --scsc-accent: #1e5a9e;\n --scsc-accent-light: #e8f0fa;\n --scsc-accent-hover: #164a82;\n --scsc-radius: 10px;\n --scsc-shadow: 0 2px 12px rgba(26, 35, 50, 0.08);\n\n font-family: system-ui, -apple-system, \"Segoe UI\", Roboto, \"Helvetica Neue\", Arial, sans-serif;\n color: var(--scsc-text);\n line-height: 1.5;\n background: var(--scsc-bg);\n border-radius: var(--scsc-radius);\n margin: 1rem 0;\n }\n\n .scsc-wrap .scsc-container {\n max-width: 960px;\n margin: 0 auto;\n padding: 2rem 1.25rem 3rem;\n }\n\n .scsc-wrap .scsc-card {\n background: var(--scsc-surface);\n border: 1px solid var(--scsc-border);\n border-radius: var(--scsc-radius);\n box-shadow: var(--scsc-shadow);\n padding: 1.5rem;\n margin-bottom: 1.25rem;\n }\n\n .scsc-wrap .scsc-card h2 {\n font-size: 1rem;\n font-weight: 600;\n color: var(--scsc-accent);\n margin: 0 0 1.25rem;\n padding-bottom: 0.5rem;\n border-bottom: 2px solid var(--scsc-accent-light);\n }\n\n .scsc-wrap .scsc-form-grid {\n display: grid;\n grid-template-columns: 1fr;\n gap: 1.25rem;\n }\n\n @media (min-width: 640px) {\n .scsc-wrap .scsc-form-grid { grid-template-columns: 1fr 1fr; }\n .scsc-wrap .scsc-form-grid .scsc-full-width { grid-column: 1 \/ -1; }\n }\n\n .scsc-wrap .scsc-field > label {\n display: block;\n font-size: 0.85rem;\n font-weight: 600;\n margin-bottom: 0.4rem;\n color: var(--scsc-text);\n }\n\n .scsc-wrap .scsc-unit {\n font-weight: 400;\n color: var(--scsc-text-muted);\n }\n\n .scsc-wrap .scsc-slider-row {\n display: flex;\n align-items: center;\n gap: 0.75rem;\n }\n\n .scsc-wrap .scsc-slider-row input[type=\"range\"] {\n flex: 1;\n accent-color: var(--scsc-accent);\n height: 6px;\n margin: 0;\n }\n\n .scsc-wrap .scsc-slider-row input[type=\"number\"] {\n width: 5.5rem;\n padding: 0.4rem 0.5rem;\n border: 1px solid var(--scsc-border);\n border-radius: 6px;\n font-size: 0.9rem;\n text-align: right;\n background: var(--scsc-surface);\n color: var(--scsc-text);\n margin: 0;\n }\n\n .scsc-wrap select,\n .scsc-wrap .scsc-custom-input {\n width: 100%;\n padding: 0.45rem 0.6rem;\n border: 1px solid var(--scsc-border);\n border-radius: 6px;\n font-size: 0.9rem;\n background: var(--scsc-surface);\n color: var(--scsc-text);\n margin: 0;\n }\n\n .scsc-wrap .scsc-custom-input { margin-top: 0.5rem; }\n\n .scsc-wrap .scsc-toggle-row {\n display: flex;\n align-items: center;\n gap: 0.75rem;\n margin-bottom: 0.75rem;\n }\n\n .scsc-wrap .scsc-toggle {\n position: relative;\n width: 44px;\n height: 24px;\n flex-shrink: 0;\n margin: 0;\n }\n\n .scsc-wrap .scsc-toggle input {\n opacity: 0;\n width: 0;\n height: 0;\n margin: 0;\n padding: 0;\n }\n\n .scsc-wrap .scsc-toggle-slider {\n position: absolute;\n inset: 0;\n background: #c5cdd8;\n border-radius: 24px;\n cursor: pointer;\n transition: background 0.2s;\n }\n\n .scsc-wrap .scsc-toggle-slider::before {\n content: \"\";\n position: absolute;\n width: 18px;\n height: 18px;\n left: 3px;\n bottom: 3px;\n background: white;\n border-radius: 50%;\n transition: transform 0.2s;\n box-shadow: 0 1px 3px rgba(0,0,0,0.2);\n }\n\n .scsc-wrap .scsc-toggle input:checked + .scsc-toggle-slider { background: var(--scsc-accent); }\n .scsc-wrap .scsc-toggle input:checked + .scsc-toggle-slider::before { transform: translateX(20px); }\n\n .scsc-wrap .scsc-toggle-label {\n font-size: 0.85rem;\n font-weight: 600;\n }\n\n .scsc-wrap .scsc-mass-field { opacity: 0.45; pointer-events: none; transition: opacity 0.2s; }\n .scsc-wrap .scsc-mass-field.scsc-enabled { opacity: 1; pointer-events: auto; }\n\n .scsc-wrap .scsc-btn-calculate {\n display: block;\n width: 33.333%;\n margin: 1.5rem auto 0;\n padding: 0.7rem 1.5rem;\n background: var(--scsc-accent) !important;\n color: #ffffff !important;\n border: none !important;\n border-radius: 8px;\n font-size: 1rem;\n font-weight: 600;\n cursor: pointer;\n letter-spacing: 0.01em;\n transition: background 0.18s, box-shadow 0.18s;\n box-shadow: 0 2px 8px rgba(30,90,158,0.18);\n text-decoration: none !important;\n }\n\n .scsc-wrap .scsc-btn-calculate:hover,\n .scsc-wrap .scsc-btn-calculate:focus,\n .scsc-wrap .scsc-btn-calculate:active {\n background: var(--scsc-accent-hover) !important;\n color: #ffffff !important;\n box-shadow: 0 4px 14px rgba(30,90,158,0.28);\n }\n\n .scsc-wrap .scsc-results-card[hidden] { display: none !important; }\n .scsc-wrap .scsc-results-card:not([hidden]) { display: block !important; }\n\n .scsc-wrap .scsc-results-primary {\n text-align: center;\n padding: 1.5rem 1rem;\n background: linear-gradient(135deg, var(--scsc-accent-light), #f0f5fc);\n border-radius: var(--scsc-radius);\n margin-bottom: 1.25rem;\n }\n\n .scsc-wrap .scsc-results-primary .scsc-value {\n font-size: 2.75rem;\n font-weight: 700;\n color: var(--scsc-accent);\n line-height: 1.1;\n font-variant-numeric: tabular-nums;\n margin: 0;\n }\n\n .scsc-wrap .scsc-results-primary .scsc-result-label {\n font-size: 0.9rem;\n color: var(--scsc-text-muted);\n margin-top: 0.25rem;\n font-weight: 500;\n }\n\n .scsc-wrap .scsc-results-grid {\n display: grid;\n grid-template-columns: repeat(2, 1fr);\n gap: 0.75rem;\n }\n\n @media (min-width: 480px) {\n .scsc-wrap .scsc-results-grid { grid-template-columns: repeat(4, 1fr); }\n }\n\n .scsc-wrap .scsc-result-item {\n background: var(--scsc-bg);\n border-radius: 8px;\n padding: 0.75rem;\n text-align: center;\n }\n\n .scsc-wrap .scsc-result-item .scsc-val {\n font-size: 1.1rem;\n font-weight: 600;\n font-variant-numeric: tabular-nums;\n color: var(--scsc-text);\n margin: 0;\n }\n\n .scsc-wrap .scsc-result-item .scsc-lbl {\n font-size: 0.72rem;\n color: var(--scsc-text-muted);\n margin-top: 0.15rem;\n }\n <\/style>\n<\/head>\n<body>\n \n <div class=\"scsc-wrap\" data-scsc=\"root\">\n <div class=\"scsc-container\">\n <section class=\"scsc-card\">\n <h2>Shaft Parameters<\/h2>\n <div class=\"scsc-form-grid\">\n <div class=\"scsc-field\">\n <label>Shaft Diameter <span class=\"scsc-unit\">(d, mm)<\/span><\/label>\n <div class=\"scsc-slider-row\">\n <input type=\"range\" data-scsc=\"diameter-slider\" min=\"10\" max=\"500\" step=\"1\" value=\"50\">\n <input type=\"number\" data-scsc=\"diameter-input\" min=\"10\" max=\"500\" step=\"1\" value=\"50\">\n <\/div>\n <\/div>\n\n <div class=\"scsc-field\">\n <label>Shaft Length <span class=\"scsc-unit\">(L, mm)<\/span><\/label>\n <div class=\"scsc-slider-row\">\n <input type=\"range\" data-scsc=\"length-slider\" min=\"100\" max=\"5000\" step=\"10\" value=\"1000\">\n <input type=\"number\" data-scsc=\"length-input\" min=\"100\" max=\"5000\" step=\"10\" value=\"1000\">\n <\/div>\n <\/div>\n\n <div class=\"scsc-field\">\n <label>Elastic Modulus <span class=\"scsc-unit\">(E)<\/span><\/label>\n <select data-scsc=\"material-e\">\n <option value=\"200\" data-rho=\"7850\" selected>Steel – 200 GPa<\/option>\n <option value=\"70\" data-rho=\"2700\">Aluminum – 70 GPa<\/option>\n <option value=\"110\" data-rho=\"4500\">Titanium – 110 GPa<\/option>\n <option value=\"100\" data-rho=\"8500\">Bronze\/Brass – 100 GPa<\/option>\n <\/select>\n <\/div>\n\n <div class=\"scsc-field\">\n <label>Material Density <span class=\"scsc-unit\">(rho, kg\/m3)<\/span><\/label>\n <select data-scsc=\"material-rho\">\n <option value=\"7850\" selected>Steel – 7850 kg\/m3<\/option>\n <option value=\"2700\">Aluminum – 2700 kg\/m3<\/option>\n <option value=\"4500\">Titanium – 4500 kg\/m3<\/option>\n <option value=\"8500\">Bronze\/Brass – 8500 kg\/m3<\/option>\n <\/select>\n <\/div>\n\n <div class=\"scsc-field scsc-full-width\">\n <label>Support \/ Boundary Conditions<\/label>\n <select data-scsc=\"boundary\">\n <option value=\"simply-supported\" selected>Simply Supported – Bearings at both ends (Pinned-Pinned)<\/option>\n <option value=\"cantilever\">Cantilever – Overhung shaft (Fixed-Free)<\/option>\n <option value=\"fixed-fixed\">Fixed-Fixed – Rigid bearings at both ends<\/option>\n <\/select>\n <\/div>\n\n <div class=\"scsc-field scsc-full-width\">\n <div class=\"scsc-toggle-row\">\n <label class=\"scsc-toggle\">\n <input type=\"checkbox\" data-scsc=\"mass-toggle\">\n <span class=\"scsc-toggle-slider\"><\/span>\n <\/label>\n <span class=\"scsc-toggle-label\">Add Central Concentrated Mass (Rotor\/Disc)<\/span>\n <\/div>\n <div class=\"scsc-mass-field\" data-scsc=\"mass-field\">\n <label>Concentrated Mass <span class=\"scsc-unit\">(M, kg)<\/span><\/label>\n <div class=\"scsc-slider-row\">\n <input type=\"range\" data-scsc=\"mass-slider\" min=\"0\" max=\"500\" step=\"1\" value=\"10\">\n <input type=\"number\" data-scsc=\"mass-input\" min=\"0\" max=\"500\" step=\"0.1\" value=\"10\">\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n <button type=\"button\" class=\"scsc-btn-calculate\" data-scsc=\"calc-btn\">Calculate<\/button>\n <\/section>\n\n <section class=\"scsc-card scsc-results-card\" data-scsc=\"results-card\" hidden>\n <h2>Results<\/h2>\n <div class=\"scsc-results-primary\">\n <div class=\"scsc-value\" data-scsc=\"critical-rpm\">–<\/div>\n <div class=\"scsc-result-label\">Critical Speed (RPM)<\/div>\n <\/div>\n <div class=\"scsc-results-grid\">\n <div class=\"scsc-result-item\">\n <div class=\"scsc-val\" data-scsc=\"critical-hz\">–<\/div>\n <div class=\"scsc-lbl\">Frequency (Hz)<\/div>\n <\/div>\n <div class=\"scsc-result-item\">\n <div class=\"scsc-val\" data-scsc=\"shaft-mass\">–<\/div>\n <div class=\"scsc-lbl\">Shaft Mass (kg)<\/div>\n <\/div>\n <div class=\"scsc-result-item\">\n <div class=\"scsc-val\" data-scsc=\"inertia\">–<\/div>\n <div class=\"scsc-lbl\">Inertia I (m4)<\/div>\n <\/div>\n <div class=\"scsc-result-item\">\n <div class=\"scsc-val\" data-scsc=\"cross-area\">–<\/div>\n <div class=\"scsc-lbl\">Area A (m2)<\/div>\n <\/div>\n <\/div>\n <\/section>\n <\/div>\n <\/div>\n\n<script type=\"text\/javascript\">\n\/* <![CDATA[ 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