{"id":100225,"date":"2026-02-15T20:28:18","date_gmt":"2026-02-15T20:28:18","guid":{"rendered":"https:\/\/vibromera.eu\/?post_type=calculator&#038;p=100225"},"modified":"2026-07-15T11:43:42","modified_gmt":"2026-07-15T11:43:42","slug":"shaft-seal-selection","status":"publish","type":"calculator","link":"https:\/\/vibromera.eu\/lt\/calculators\/shaft-seal-selection\/","title":{"rendered":"Documented Seal-Counterface Surface-Speed Worksheet"},"content":{"rendered":"\n<style>\n.vbm225{--ink:#172235;--muted:#556276;--line:#d8e0e9;--soft:#f4f7fa;--blue:#135ca8;--blue2:#0d447e;--amber:#8a5700;--amber-bg:#fff7df;--red:#a52828;--red-bg:#fff0f0;--green:#17613a;--green-bg:#edf9f1;max-width:1040px;margin:0 auto;padding:18px 14px 44px;color:var(--ink);font:15px\/1.55 system-ui,-apple-system,\"Segoe UI\",sans-serif}.vbm225 *{box-sizing:border-box}.vbm225 h1,.vbm225 h2,.vbm225 h3{line-height:1.2}.vbm225 h1{font-size:clamp(27px,4vw,42px);margin:8px 0 12px}.vbm225 h2{font-size:22px;margin:0 0 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.vbm225-result-value{font-size:23px;color:var(--blue2)}.vbm225-status{margin-top:14px;border-left:4px solid var(--green);background:var(--green-bg);padding:12px 14px}.vbm225-formula{overflow-x:auto;border:1px solid var(--line);border-radius:9px;background:var(--soft);padding:12px 14px;margin:10px 0;font:600 14px\/1.7 ui-monospace,SFMono-Regular,Consolas,monospace}.vbm225 table{width:100%;border-collapse:collapse;margin:12px 0}.vbm225 th,.vbm225 td{border:1px solid var(--line);padding:9px 10px;text-align:left;vertical-align:top}.vbm225 th{background:#eaf0f6}.vbm225 ul{padding-left:22px}.vbm225 details{border-top:1px solid var(--line);padding:11px 0}.vbm225 summary{cursor:pointer;font-weight:760}.vbm225-small{font-size:13px;color:var(--muted)}\n@media(max-width:700px){.vbm225{padding-left:10px;padding-right:10px}.vbm225-card{padding:16px}.vbm225-grid,.vbm225-result-grid{grid-template-columns:1fr}.vbm225-result.primary,.vbm225-field.full{grid-column:auto}.vbm225 table{display:block;overflow-x:auto;white-space:normal}.vbm225-inline{grid-template-columns:minmax(0,1fr) 105px}}\n<\/style>\n<main class=\"vbm225\">\n  <header class=\"vbm225-header\">\n    <p class=\"vbm225-kicker\">Seal-counterface kinematics \u00b7 documented inputs<\/p>\n    <h1>Documented Seal-Counterface Surface-Speed Worksheet<\/h1>\n    <p class=\"vbm225-lead\">Calculate circumferential speed from the actual counterface diameter and rotational speed, while preserving the supplier, application and review record needed for a separate seal-selection decision.<\/p>\n    <div class=\"vbm225-badges\"><span class=\"vbm225-badge\">v = \u03c0dn<\/span><span class=\"vbm225-badge\">Metric and inch inputs<\/span><span class=\"vbm225-badge\">No automatic seal selection<\/span><\/div>\n  <\/header>\n\n  <div class=\"vbm225-notice\"><strong>Kinematics only \u2014 not a seal recommendation or acceptance verdict.<\/strong> This worksheet does not choose a seal size, design or material; does not supply an allowable speed, pressure, temperature or surface-finish limit; and does not certify conformity with ISO 6194. Verify the exact part number and the complete application envelope in the controlled manufacturer catalogue and project specification.<\/div>\n\n  <form id=\"vbm225-form\" class=\"vbm225-card\" autocomplete=\"off\" novalidate>\n    <h2>Actual counterface and controlled record<\/h2>\n    <div class=\"vbm225-grid\">\n      <div class=\"vbm225-field\"><label for=\"vbm225-diameter\">Actual seal-counterface diameter<\/label><div class=\"vbm225-inline\"><input id=\"vbm225-diameter\" type=\"text\" inputmode=\"decimal\" placeholder=\"e.g. 40\"><select id=\"vbm225-dunit\" aria-label=\"Diameter unit\"><option value=\"mm\">mm<\/option><option value=\"in\">in<\/option><\/select><\/div><span class=\"vbm225-hint\">Positive plain decimal; point or comma.<\/span><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-speed\">Rotational-speed magnitude<\/label><div class=\"vbm225-inline\"><input id=\"vbm225-speed\" type=\"text\" inputmode=\"decimal\" placeholder=\"e.g. 1500\"><select id=\"vbm225-sunit\" aria-label=\"Rotational-speed unit\"><option value=\"rpm\">r\/min<\/option><option value=\"hz\">rev\/s (Hz)<\/option><\/select><\/div><span class=\"vbm225-hint\">Zero is accepted for a stationary shaft; negative values are rejected.<\/span><\/div>\n\n      <div class=\"vbm225-field\"><label for=\"vbm225-project\">Project \/ equipment<\/label><input id=\"vbm225-project\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-feature\">Shaft \/ counterface identifier<\/label><input id=\"vbm225-feature\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-drawing\">Drawing \/ revision \/ dimensional callout<\/label><input id=\"vbm225-drawing\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-seal\">Seal manufacturer \/ exact designation<\/label><input id=\"vbm225-seal\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-catalogue\">Controlled supplier catalogue \/ revision \/ page<\/label><input id=\"vbm225-catalogue\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-medium\">Medium: exact name \/ grade \/ concentration<\/label><input id=\"vbm225-medium\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-temperature\">Bulk and estimated lip-temperature basis<\/label><input id=\"vbm225-temperature\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-pressure\">Pressure differential and transients<\/label><input id=\"vbm225-pressure\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-lubrication\">Lubrication and heat-dissipation condition<\/label><input id=\"vbm225-lubrication\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-design\">Seal design \/ lip material \/ auxiliary lip<\/label><input id=\"vbm225-design\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-surface\">Counterface material \/ hardness \/ finish<\/label><input id=\"vbm225-surface\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-geometry\">Runout \/ lead \/ alignment requirement record<\/label><input id=\"vbm225-geometry\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-prepared\">Prepared \/ reviewed by<\/label><input id=\"vbm225-prepared\" type=\"text\" placeholder=\"required\"><\/div>\n      <div class=\"vbm225-field\"><label for=\"vbm225-date\">Record date<\/label><input id=\"vbm225-date\" type=\"text\" placeholder=\"YYYY-MM-DD\"><\/div>\n      <div class=\"vbm225-field full\"><label for=\"vbm225-notes\">Notes and exclusions <span class=\"vbm225-hint\">Optional: duty cycle, direction, contamination, installation, storage and inspection records<\/span><\/label><textarea id=\"vbm225-notes\"><\/textarea><\/div>\n    <\/div>\n    <div class=\"vbm225-checks\">\n      <label class=\"vbm225-check\"><input type=\"checkbox\" id=\"vbm225-c1\"><span>The diameter is the actual running counterface diameter for the documented sealing lip, not a rounded catalogue or neighbouring shaft size.<\/span><\/label>\n      <label class=\"vbm225-check\"><input type=\"checkbox\" id=\"vbm225-c2\"><span>The entered speed represents the controlled maximum or duty point relevant to this record.<\/span><\/label>\n      <label class=\"vbm225-check\"><input type=\"checkbox\" id=\"vbm225-c3\"><span>The exact supplier data were checked separately for design, material compatibility, pressure, temperature, lubrication, counterface, runout, lead, installation and duty-cycle requirements.<\/span><\/label>\n      <label class=\"vbm225-check\"><input type=\"checkbox\" id=\"vbm225-c4\"><span>I understand that the calculated surface speed alone cannot establish seal suitability or ISO 6194 conformity.<\/span><\/label>\n    <\/div>\n    <div class=\"vbm225-actions\"><button type=\"submit\" class=\"vbm225-primary\">Calculate documented speed<\/button><button type=\"button\" class=\"vbm225-secondary\" id=\"vbm225-clear\">Clear<\/button><\/div>\n    <div id=\"vbm225-error\" class=\"vbm225-error\" role=\"alert\"><\/div>\n  <\/form>\n\n  <section id=\"vbm225-results\" class=\"vbm225-card vbm225-results\" aria-live=\"polite\">\n    <h2>Reference kinematic results<\/h2>\n    <div class=\"vbm225-result-grid\">\n      <div class=\"vbm225-result primary\"><div class=\"vbm225-result-label\">Counterface surface speed<\/div><div class=\"vbm225-result-value\" id=\"vbm225-r-speed\">\u2014<\/div><\/div>\n      <div class=\"vbm225-result\"><div class=\"vbm225-result-label\">Counterface circumference<\/div><div class=\"vbm225-result-value\" id=\"vbm225-r-circ\">\u2014<\/div><\/div>\n      <div class=\"vbm225-result\"><div class=\"vbm225-result-label\">Rotational frequency<\/div><div class=\"vbm225-result-value\" id=\"vbm225-r-frequency\">\u2014<\/div><\/div>\n      <div class=\"vbm225-result\"><div class=\"vbm225-result-label\">Angular speed<\/div><div class=\"vbm225-result-value\" id=\"vbm225-r-angular\">\u2014<\/div><\/div>\n      <div class=\"vbm225-result\"><div class=\"vbm225-result-label\">Sliding distance in one hour at steady speed<\/div><div class=\"vbm225-result-value\" id=\"vbm225-r-distance\">\u2014<\/div><\/div>\n      <div class=\"vbm225-result\"><div class=\"vbm225-result-label\">Normalized inputs<\/div><div class=\"vbm225-result-value\" id=\"vbm225-r-inputs\">\u2014<\/div><\/div>\n    <\/div>\n    <div class=\"vbm225-status\" id=\"vbm225-r-status\"><\/div>\n  <\/section>\n\n  <section class=\"vbm225-card\">\n    <h2>Equations and dimensional check<\/h2>\n    <p>For actual counterface diameter d in metres and rotational frequency f in revolutions per second:<\/p>\n    <div class=\"vbm225-formula\">circumference C = \u03c0d<br>surface speed v = Cf = \u03c0df<br>f = n\/60, when n is in r\/min<br>angular speed \u03c9 = 2\u03c0f<\/div>\n    <p>Therefore, for d in millimetres and n in r\/min:<\/p>\n    <div class=\"vbm225-formula\">v [m\/s] = \u03c0 \u00d7 d [mm] \u00d7 n [r\/min] \/ 60,000<\/div>\n    <p>This is a geometry-and-time identity, not an \u201cISO 6194 formula.\u201d Metres per revolution multiplied by revolutions per second gives metres per second. Exact conversions used are 1 in = 25.4 mm and 1 m\/s = 196.8503937007874 ft\/min.<\/p>\n  <\/section>\n\n  <section class=\"vbm225-card\">\n    <h2>Model boundary and removed unsafe logic<\/h2>\n    <ul>\n      <li><strong>No nearest-size substitution.<\/strong> The former page silently replaced an entered non-table shaft diameter with the next stored diameter (or the largest stored size), then calculated speed using that different diameter. This worksheet always uses the actual entered counterface diameter.<\/li>\n      <li><strong>No invented preferred-size table.<\/strong> ISO 6194-1 covers nominal dimensions and tolerances for its scope, but an exact permissible part must be verified from the controlled standard and manufacturer product data. Exact tables and tolerances remain <code>NEEDS_LICENSED_SOURCE<\/code>.<\/li>\n      <li><strong>No universal material rule.<\/strong> NBR, FKM, PTFE or EPDM cannot be selected safely from medium name and bulk temperature alone. Compound, concentration, lip temperature, pressure, lubrication, design, counterface and supplier qualification matter.<\/li>\n      <li><strong>No fixed universal speed limit.<\/strong> SKF states that acceptable speed depends on seal design and lip material, shaft material and condition, lubrication and lubricant; its comparison diagram also assumes normal operation and no pressure differential. Use the limit for the exact product and application.<\/li>\n      <li><strong>No pressure, finish or hardness verdict.<\/strong> Those requirements are not calculated here. Use the controlled drawing, selected manufacturer data, applicable standard clauses, uncertainty and engineering review.<\/li>\n      <li><strong>No conformance decision.<\/strong> ISO 6194 parts address different subjects including dimensions\/tolerances, vocabulary, handling\/installation, testing and visual imperfections. A surface-speed calculation alone does not prove conformity with any part.<\/li>\n    <\/ul>\n  <\/section>\n\n  <section class=\"vbm225-card\">\n    <h2>Source traceability<\/h2>\n    <table><thead><tr><th>Claim<\/th><th>Classification<\/th><th>Evidence<\/th><\/tr><\/thead><tbody>\n      <tr><td>v = \u03c0dn\/60,000 for d in mm and n in r\/min<\/td><td>General geometric identity; not an ISO formula<\/td><td>Derived above; independently equivalent to SKF CR Seals Handbook metric conversion d \u00d7 r\/min \u00f7 19,100 (rounded denominator)<\/td><\/tr>\n      <tr><td>Acceptable seal speed depends on design\/material, shaft condition, lubrication\/lubricant and operating assumptions<\/td><td>Manufacturer application guidance<\/td><td><a href=\"https:\/\/www.skf.com\/binaries\/pub12\/Images\/0901d196807662c1-810-701_CRSeals_Handbook_Jan_2019_tcm_12-318140.pdf\" rel=\"noopener\" target=\"_blank\">SKF CR Seals Handbook, Engineering \u2014 Special considerations, p. 42<\/a><\/td><\/tr>\n      <tr><td>Nominal dimensions\/tolerances for seals, shafts and housings; elastomeric elements and low-pressure scope<\/td><td>Current standard scope\/status only; exact values not reproduced<\/td><td><a href=\"https:\/\/www.iso.org\/standard\/34678.html\" rel=\"noopener\" target=\"_blank\">ISO 6194-1:2007<\/a>, Edition 2, published and confirmed in 2023<\/td><\/tr>\n      <tr><td>Vocabulary for elastomeric sealing elements and low-pressure scope<\/td><td>Current standard scope\/status only<\/td><td><a href=\"https:\/\/www.iso.org\/standard\/45846.html\" rel=\"noopener\" target=\"_blank\">ISO 6194-2:2009<\/a>, Edition 2, published and confirmed in 2025<\/td><\/tr>\n      <tr><td>Storage, handling and installation requirements\/guidance<\/td><td>Current standard scope\/status only<\/td><td><a href=\"https:\/\/www.iso.org\/standard\/43009.html\" rel=\"noopener\" target=\"_blank\">ISO 6194-3:2009<\/a>, Edition 2, published and confirmed in 2025<\/td><\/tr>\n      <tr><td>General test requirements that may be used for qualification<\/td><td>Current standard scope\/status only<\/td><td><a href=\"https:\/\/www.iso.org\/standard\/43010.html\" rel=\"noopener\" target=\"_blank\">ISO 6194-4:2009<\/a>, Edition 3, published; under systematic review in 2026<\/td><\/tr>\n      <tr><td>Identification\/classification of visual imperfections<\/td><td>Current standard scope\/status only<\/td><td><a href=\"https:\/\/www.iso.org\/standard\/42162.html\" rel=\"noopener\" target=\"_blank\">ISO 6194-5:2008<\/a>, Edition 2, published and confirmed in 2022<\/td><\/tr>\n      <tr><td>Proposed material-properties work<\/td><td>Working draft; not a normative source<\/td><td><a href=\"https:\/\/www.iso.org\/standard\/93226.html\" rel=\"noopener\" target=\"_blank\">ISO\/WD 6194-6<\/a>, under development as of 2026<\/td><\/tr>\n      <tr><td>1 in = 25.4 mm exactly<\/td><td>Exact SI conversion<\/td><td><a href=\"https:\/\/www.nist.gov\/pml\/special-publication-811\/nist-guide-si-appendix-b-conversion-factors\/nist-guide-si-appendix-b8\" rel=\"noopener\" target=\"_blank\">NIST SP 811, Appendix B.8<\/a><\/td><\/tr>\n    <\/tbody><\/table>\n    <p class=\"vbm225-small\"><strong>Accessed:<\/strong> 15 July 2026. Public sources establish the displayed scopes\/status and kinematic conversion. They do not establish an allowable value or select a seal for the recorded application. Worksheet URL: https:\/\/vibromera.eu\/calculators\/shaft-seal-selection\/<\/p>\n    <h3>Reference example<\/h3>\n    <p>For an actual 40 mm counterface at 1,500 r\/min: f = 25 Hz, circumference = 125.663706 mm, v = \u03c0 m\/s \u2248 3.141592654 m\/s, \u03c9 = 50\u03c0 rad\/s \u2248 157.0796327 rad\/s, and one-hour sliding distance = 11.30973355 km. This checks the implementation; it is not a seal-speed limit.<\/p>\n  <\/section>\n\n  <section class=\"vbm225-card\">\n    <h2>Questions<\/h2>\n    <details><summary>Why does the worksheet no longer recommend a seal size?<\/summary><p>A lip seal is not interchangeable merely because a stored diameter is close. Shaft diameter, housing bore, width, tolerances, exact product design and application conditions must match controlled data. The previous nearest-size substitution could recommend a seal for a different shaft.<\/p><\/details>\n    <details><summary>Can surface speed select NBR, FKM, PTFE or EPDM?<\/summary><p>No. Surface speed is one input. Compound-specific chemical compatibility, actual lip temperature, pressure, lubrication, shaft condition, design and supplier qualification must also be checked.<\/p><\/details>\n    <details><summary>Does a result below a catalogue diagram guarantee suitability?<\/summary><p>No. Manufacturer diagrams have stated assumptions and may require reductions or product-specific checks. Use the exact product record, not a generic comparison alone.<\/p><\/details>\n    <details><summary>Is this calculation ISO 6194 compliant?<\/summary><p>The calculation is a general kinematic identity. It does not test the requirements of ISO 6194 or produce a conformance decision. Exact clauses, dimensional tables and tolerances are <code>NEEDS_LICENSED_SOURCE<\/code> unless a controlled document is supplied.<\/p><\/details>\n  <\/section>\n<\/main>\n<script>\n(function(){\n'use strict';\nvar form=document.getElementById('vbm225-form'),error=document.getElementById('vbm225-error'),results=document.getElementById('vbm225-results');\nfunction parseDecimal(value,label){var s=String(value==null?'':value).trim();if(!\/^[+-]?(?:\\d+(?:[.,]\\d*)?|[.,]\\d+)$\/.test(s))throw new Error(label+' must be one plain decimal using a point or comma.');var n=Number(s.replace(',','.'));if(!Number.isFinite(n))throw new Error(label+' is outside the finite numeric range.');return n}\nfunction requiredText(id,label){var value=document.getElementById(id).value.trim();if(!value)throw new Error(label+' is required.');return value}\nfunction calculate(values){if(!['mm','in'].includes(values.dunit))throw new Error('Select a valid diameter unit.');if(!['rpm','hz'].includes(values.sunit))throw new Error('Select a valid rotational-speed unit.');var enteredD=parseDecimal(values.diameter,'Counterface diameter'),enteredS=parseDecimal(values.speed,'Rotational speed');if(!(enteredD>0))throw new Error('Counterface diameter must be greater than zero.');if(enteredS<0)throw new Error('Rotational speed must not be negative.');var dmm=values.dunit==='mm'?enteredD:enteredD*25.4,rpm=values.sunit==='rpm'?enteredS:enteredS*60,hz=rpm\/60,circMm=Math.PI*dmm,v=Math.PI*(dmm\/1000)*hz,omega=2*Math.PI*hz,ftmin=v*196.8503937007874,distanceKm=v*3.6;var out=[dmm,rpm,hz,circMm,v,omega,ftmin,distanceKm];if(!out.every(Number.isFinite))throw new Error('The result is outside the finite numeric range.');return{dmm:dmm,rpm:rpm,hz:hz,circMm:circMm,v:v,omega:omega,ftmin:ftmin,distanceKm:distanceKm}}\nfunction fmt(n){if(!Number.isFinite(n))return'\u2014';if(Object.is(n,-0)||n===0)return'0';var a=Math.abs(n);return(a>=1e8||a<1e-6?n.toExponential(7):n.toPrecision(9)).replace(\/(\\.\\d*?[1-9])0+(e|$)\/,'$1$2').replace(\/\\.0+(e|$)\/,'$1')}\nfunction setText(id,text){document.getElementById(id).textContent=text}\nfunction render(r){setText('vbm225-r-speed',fmt(r.v)+' m\/s \u00b7 '+fmt(r.ftmin)+' ft\/min');setText('vbm225-r-circ',fmt(r.circMm)+' mm \u00b7 '+fmt(r.circMm\/25.4)+' in');setText('vbm225-r-frequency',fmt(r.hz)+' Hz \u00b7 '+fmt(r.rpm)+' r\/min');setText('vbm225-r-angular',fmt(r.omega)+' rad\/s');setText('vbm225-r-distance',fmt(r.distanceKm)+' km');setText('vbm225-r-inputs',fmt(r.dmm)+' mm \u00b7 '+fmt(r.rpm)+' r\/min');setText('vbm225-r-status','Kinematic result only. No allowable speed, material, seal size, ISO conformity or acceptance verdict has been generated. 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