{"id":679,"date":"2025-02-26T14:02:11","date_gmt":"2025-02-26T06:02:11","guid":{"rendered":"https:\/\/hengoseal.com\/?p=679"},"modified":"2025-04-25T14:15:48","modified_gmt":"2025-04-25T06:15:48","slug":"metric-buna-o-rings-guide","status":"publish","type":"post","link":"https:\/\/hengoseal.com\/eo\/metric-buna-o-rings-guide\/","title":{"rendered":"Metric Buna O Rings: How to Measure &#038; Choose the Best Fit in 2025?"},"content":{"rendered":"<p>Struggling with seal fit and leaks in hydraulic or pneumatic systems? <strong>Metric Buna O Rings<\/strong> may be the exact solution you need\u2014let me explain why.<br \/>\nMetric Buna O Rings offer precise fit and excellent oil resistance, ideal for modern industrial sealing. Here's how to measure, select, and source the right one.<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/hengoseal.com\/wp-content\/uploads\/2025\/02\/metric-buna-o-rings-1-2.jpg\" alt=\"placeholder_image\" \/><\/p>\n<p>This guide helps you select the best <strong>metric Buna O ring<\/strong> based on your system specs\u2014covering sizes, materials, pressure, and oil compatibility.<\/p>\n<h2>What are metric Buna O rings used for?<\/h2>\n<p>Metric Buna O Rings are essential for sealing in metric-based systems.<br \/>\nThey're used in hydraulic cylinders, pneumatic valves, fuel systems, and industrial machinery.<\/p>\n<p>Metric Buna O Rings are made from NBR (nitrile rubber), offering excellent resistance to oils, fuels, and abrasion. Commonly found in European and Asian equipment, they are ideal where inch-sized O rings don\u2019t fit. They're widely used in:<\/p>\n<ul>\n<li>Hydraulic cylinders to prevent leakage  <\/li>\n<li>Pneumatic systems to maintain pressure  <\/li>\n<li>Automotive fuel systems for reliable sealing  <\/li>\n<\/ul>\n<p>Vi anka\u016d povas esplori nian <a href=\"https:\/\/hengoseal.com\/eo\/buna-o-rings-guide\/\" target=\"_blank\">complete Buna O Ring guide<\/a> for a deeper dive into NBR\u2019s advantages.<\/p>\n<h2>How do I measure a metric O ring?<\/h2>\n<p>Correct measurements ensure leak-proof performance.<br \/>\nYou\u2019ll need to measure the ID, CS, and calculate the OD.<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/hengoseal.com\/wp-content\/uploads\/2025\/02\/8.FKM-O-RING-OD110-5.7mm-scaled.jpg\" alt=\"placeholder_image\" \/><\/p>\n<p>To measure a metric Buna O Ring:<\/p>\n<ol>\n<li><strong>Interna Diametro (ID)<\/strong> \u2013 Measure across the inside.  <\/li>\n<li><strong>Sekco (CS)<\/strong> \u2013 Measure the ring\u2019s thickness.  <\/li>\n<li><strong>Ekstera Diametro (OD)<\/strong> \u2013 Use the formula: OD = ID + 2 \u00d7 CS.  <\/li>\n<li><strong>Komparu kun grandeco-diagramoj<\/strong> \u2013 Use an AS568 or ISO chart to match.<\/li>\n<\/ol>\n<p>Common sizes include:<\/p>\n<table>\n<thead>\n<tr>\n<th>ID (mm)<\/th>\n<th>CS (mm)<\/th>\n<th>Apliko<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>10.0<\/td>\n<td>2.0<\/td>\n<td>Pumps, valvoj<\/td>\n<\/tr>\n<tr>\n<td>18.8<\/td>\n<td>1.9<\/td>\n<td>Pne\u016dmatikaj cilindroj<\/td>\n<\/tr>\n<tr>\n<td>22.4<\/td>\n<td>3.1<\/td>\n<td>A\u016dtomobilaj komponantoj<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Need a broader range? Try our <a href=\"https:\/\/hengoseal.com\/eo\/o-ring-assortment-kit-guide\/\" target=\"_blank\">O Ring Assortment Kit<\/a> for fast inventory management.<\/p>\n<h2>Are metric Buna O rings compatible with hydraulic fluid?<\/h2>\n<p>Yes\u2014Buna O Rings are ideal for hydraulic oil sealing.<br \/>\nThey resist mineral-based oils and seal reliably under pressure.<\/p>\n<p>Metric Buna O Rings offer excellent performance in hydraulic fluid systems:<\/p>\n<ul>\n<li><strong>Hydraulic actuators<\/strong> - Malhelpi elfluon  <\/li>\n<li><strong>High-pressure valves<\/strong> \u2013 Maintain system stability  <\/li>\n<li><strong>Pump seals<\/strong> \u2013 Withstand fluid exposure and wear  <\/li>\n<\/ul>\n<p>For more demanding environments (e.g., with high temp or strong chemicals), consider <a href=\"https:\/\/hengoseal.com\/eo\/varo\/fkm-o-ring\/\" target=\"_blank\">FKM O Rings for heat sealing<\/a> a\u016d <a href=\"https:\/\/hengoseal.com\/eo\/varo\/epdm-o-ring\/\" target=\"_blank\">EPDM O Rings for steam &amp; water resistance<\/a>.<\/p>\n<h2>How do I select the right metric Buna O ring?<\/h2>\n<p>Selection depends on pressure, fluid, and environmental exposure.<br \/>\nYou\u2019ll need to evaluate material, durometer, and system specs.<\/p>\n<p>Here\u2019s a breakdown to guide your choice:<\/p>\n<table>\n<thead>\n<tr>\n<th>Faktoro<\/th>\n<th>Plej bona Praktiko<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Materialo<\/td>\n<td>Ensure NBR fits your chemical exposure<\/td>\n<\/tr>\n<tr>\n<td>Size Accuracy<\/td>\n<td>Use precise calipers for fit<\/td>\n<\/tr>\n<tr>\n<td>Temperaturgamo<\/td>\n<td>Buna handles -40\u00b0C to 120\u00b0C comfortably<\/td>\n<\/tr>\n<tr>\n<td>Taksado de Premo<\/td>\n<td>Use 90 Shore hardness for high-pressure applications<\/td>\n<\/tr>\n<tr>\n<td>Alternative Options<\/td>\n<td>Uzu <a href=\"https:\/\/hengoseal.com\/eo\/epdm-vs-fkm-o-rings\/\" target=\"_blank\">FKM or EPDM<\/a> for heat or steam resistance<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Need help choosing? Ask our team for guidance on <a href=\"https:\/\/wa.me\/8617622979498\" target=\"_blank\" rel=\"nofollow noopener\">WhatsApp<\/a> or check our <a href=\"https:\/\/hengoseal.com\/eo\/varo\/nitrile-o-ring\/\" target=\"_blank\">NBR O-Ring product line<\/a>.<\/p>\n<h2>Where can I buy metric Buna O rings in bulk?<\/h2>\n<p>Buy directly from trusted industrial suppliers like Hengoseal.<br \/>\nWe offer global delivery, custom sizing, and low MOQ.<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/hengoseal.com\/wp-content\/uploads\/2025\/02\/Sample-.jpg\" alt=\"placeholder_image\" \/><\/p>\n<p>At Hengoseal, you\u2019ll find:<\/p>\n<ul>\n<li><strong>Custom-molded metric Buna O Rings<\/strong><\/li>\n<li><strong>Bulk order discounts<\/strong> for manufacturers<\/li>\n<li><strong>Fast global fulfillment<\/strong><\/li>\n<\/ul>\n<p>Need sealing for various applications? Our <a href=\"https:\/\/hengoseal.com\/eo\/varo\/o-ring-assortment\/\" target=\"_blank\">O Ring Assortment Kit<\/a> is also available for on-the-go repairs.<\/p>\n<h2>Konkludo<\/h2>\n<p>Metric Buna O Rings ensure precise sealing for hydraulic, pneumatic, and fuel systems\u2014especially where inch-based rings don\u2019t fit.<\/p>\n<h2>Browse metric sizes &amp; get expert help today<\/h2>\n<p>\ud83d\udce9 Retpo\u015dto: info@hengoseal.com<br \/>\n\ud83d\udcde WhatsApp: +86 17622979498  <\/p>\n<h2>Related topic<\/h2>\n<ul>\n<li><a href=\"https:\/\/hengoseal.com\/eo\/buna-o-rings-guide\/\" target=\"_blank\">Buna O Rings: \u0108io, kion Vi Devas Scii<\/a>  <\/li>\n<li><a href=\"https:\/\/hengoseal.com\/eo\/o-ring-assortment-kit-guide\/\" target=\"_blank\">O Ring Assortment Kit: Selection Made Simple<\/a>  <\/li>\n<li><a href=\"https:\/\/hengoseal.com\/eo\/fkm-o-rings-high-temperature-sealing\/\" target=\"_blank\">FKM O Rings for Heat Resistance<\/a>  <\/li>\n<li><a href=\"https:\/\/hengoseal.com\/eo\/nitrile-rubber-o-rings-guide\/\" target=\"_blank\">Nitrile Rubber O Rings: Oil-Resistant Choice<\/a>  <\/li>\n<li><a href=\"https:\/\/hengoseal.com\/eo\/o-ring-seal-guide\/\" target=\"_blank\">O Ring Seal: The Ultimate Leak Prevention Guide<\/a><\/li>\n<\/ul>\n<style>\n.faq-question {\ncursor: pointer;\nfont-weight: bold;\npadding: 10px;\nbackground-color: #f1f1f1;\nborder: 1px solid #ddd;\nmargin-bottom: 5px;\ncolor: #0073aa;\n}\n.faq-answer {\ndisplay: none;\npadding: 10px;\nborder-left: 3px solid #0073aa;\nbackground-color: #f9f9f9;\nmargin-bottom: 10px;\n}\n<\/style>\n<p><script>\ndocument.addEventListener('DOMContentLoaded', function() {\nconst questions = document.querySelectorAll('.faq-question');\nquestions.forEach(question => {\nquestion.addEventListener('click', function() {\nconst answer = this.nextElementSibling;\nanswer.style.display = answer.style.display === 'block' ? 'none' : 'block';\n});\n});\n});\n<\/script><br \/>\n<!-- JSON-LD FAQ Schema --><br \/>\n<script type=\"application\/ld+json\">\n{\n\"@context\": \"https:\/\/schema.org\",\n\"@type\": \"FAQPage\",\n\"mainEntity\": [\n{\n\"@type\": \"Question\",\n\"name\": \"Can I use metric Buna O rings in fuel systems?\",\n\"acceptedAnswer\": {\n\"@type\": \"Answer\",\n\"text\": \"Yes, they perform well with petroleum-based fuels and oils.\"\n}\n},\n{\n\"@type\": \"Question\",\n\"name\": \"What hardness is standard for metric Buna O rings?\",\n\"acceptedAnswer\": {\n\"@type\": \"Answer\",\n\"text\": \"Most are 70 Shore A, but 90 Shore is available for high pressure.\"\n}\n},\n{\n\"@type\": \"Question\",\n\"name\": \"How long do metric Buna O rings last?\",\n\"acceptedAnswer\": {\n\"@type\": \"Answer\",\n\"text\": \"Typically 5&ndash;10 years, depending on exposure and storage.\"\n}\n},\n{\n\"@type\": \"Question\",\n\"name\": \"Are metric and inch O rings interchangeable?\",\n\"acceptedAnswer\": {\n\"@type\": \"Answer\",\n\"text\": \"Not usually. Always compare ID and CS before substituting.\"\n}\n},\n{\n\"@type\": \"Question\",\n\"name\": \"What if I need FDA-grade material?\",\n\"acceptedAnswer\": {\n\"@type\": \"Answer\",\n\"text\": \"Consider switching to silicone or EPDM for food-grade compliance.\"\n}\n},\n{\n\"@type\": \"Question\",\n\"name\": \"Can metric Buna O rings handle steam?\",\n\"acceptedAnswer\": {\n\"@type\": \"Answer\",\n\"text\": \"Not ideal&mdash;<a href=\\\"https:\/\/hengoseal.com\/product\/epdm-o-ring\/\\\" target=\\\"_blank\\\">EPDM is better for steam and high temp moisture.\"\n}\n},\n{\n\"@type\": \"Question\",\n\"name\": \"Do you offer custom-molded metric sizes?\",\n\"acceptedAnswer\": {\n\"@type\": \"Answer\",\n\"text\": \"Yes, we offer full customization with low minimums.\"\n}\n},\n{\n\"@type\": \"Question\",\n\"name\": \"Where can I find size charts for metric O rings?\",\n\"acceptedAnswer\": {\n\"@type\": \"Answer\",\n\"text\": \"Refer to our <a href=\\\"https:\/\/hengoseal.com\/o-ring-assortment-kit-guide\/\\\" target=\\\"_blank\\\">size guide in the O Ring Kit article.\"\n}\n}\n]\n}\n<\/script><\/p>\n<h2>Homoj Anka\u016d Demandas<\/h2>\n<div class=\"faq-container\">\n<div class=\"faq-question\">1. Can I use metric Buna O rings in fuel systems?<\/div>\n<div class=\"faq-answer\">Yes, they perform well with petroleum-based fuels and oils.<\/div>\n<\/div>\n<div class=\"faq-container\">\n<div class=\"faq-question\">2. What hardness is standard for metric Buna O rings?<\/div>\n<div class=\"faq-answer\">Most are 70 Shore A, but 90 Shore is available for high pressure.<\/div>\n<\/div>\n<div class=\"faq-container\">\n<div class=\"faq-question\">3. How long do metric Buna O rings last?<\/div>\n<div class=\"faq-answer\">Typically 5\u201310 years, depending on exposure and storage.<\/div>\n<\/div>\n<div class=\"faq-container\">\n<div class=\"faq-question\">4. Are metric and inch O rings interchangeable?<\/div>\n<div class=\"faq-answer\">Not usually. Always compare ID and CS before substituting.<\/div>\n<\/div>\n<div class=\"faq-container\">\n<div class=\"faq-question\">5. What if I need FDA-grade material?<\/div>\n<div class=\"faq-answer\">Consider switching to silicone or EPDM for food-grade compliance.<\/div>\n<\/div>\n<div class=\"faq-container\">\n<div class=\"faq-question\">6. Can metric Buna O rings handle steam?<\/div>\n<div class=\"faq-answer\">Not ideal\u2014<a href=\"https:\/\/hengoseal.com\/eo\/varo\/epdm-o-ring\/\" target=\"_blank\">EPDM<\/a> is better for steam and high temp moisture.<\/div>\n<\/div>\n<div class=\"faq-container\">\n<div class=\"faq-question\">7. Do you offer custom-molded metric sizes?<\/div>\n<div class=\"faq-answer\">Yes, we offer full customization with low minimums.<\/div>\n<\/div>\n<div class=\"faq-container\">\n<div class=\"faq-question\">8. Where can I find size charts for metric O rings?<\/div>\n<div class=\"faq-answer\">Refer to our <a href=\"https:\/\/hengoseal.com\/eo\/o-ring-assortment-kit-guide\/\" target=\"_blank\">size guide in the O Ring Kit article<\/a>.<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Struggling with seal fit and leaks in hydraulic or pneumatic systems? Metric Buna O Rings may be the exact solution [&hellip;]<\/p>","protected":false},"author":1,"featured_media":680,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[37],"tags":[],"class_list":["post-679","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-o-ring-seals"],"_links":{"self":[{"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/posts\/679","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/comments?post=679"}],"version-history":[{"count":0,"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/posts\/679\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/media\/680"}],"wp:attachment":[{"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/media?parent=679"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/categories?post=679"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hengoseal.com\/eo\/wp-json\/wp\/v2\/tags?post=679"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}