{"id":1997,"date":"2026-02-22T06:29:29","date_gmt":"2026-02-22T06:29:29","guid":{"rendered":"https:\/\/www.wonzh.com\/?p=1997"},"modified":"2026-02-22T06:30:38","modified_gmt":"2026-02-22T06:30:38","slug":"8-critical-tolerances-to-control-in-custom-cnc-machined-parts","status":"publish","type":"post","link":"https:\/\/www.wonzh.com\/ja\/8-critical-tolerances-to-control-in-custom-cnc-machined-parts\/","title":{"rendered":"\u30ab\u30b9\u30bf\u30e0CNC\u6a5f\u68b0\u52a0\u5de5\u90e8\u54c1\u3067\u7ba1\u7406\u3059\u3079\u304d8\u3064\u306e\u91cd\u8981\u516c\u5dee"},"content":{"rendered":"<p>In industrial equipment and mechanical assemblies, dimensional tolerance is not just a drawing requirement \u2014 it directly affects assembly accuracy, operational stability, and long-term reliability.<\/p>\n\n\n\n<p>For OEM buyers and maintenance engineers, understanding which tolerances are truly critical can significantly reduce failure rates and unnecessary production costs.<\/p>\n\n\n\n<p>Below are <strong>8 critical tolerances<\/strong> that must be properly controlled in custom <a href=\"https:\/\/www.wonzh.com\/ja\/product-category\/%e7%b2%be%e5%af%86%e6%a9%9f%e6%a2%b0%e5%8a%a0%e5%b7%a5%e9%83%a8%e5%93%81\/\"><mark style=\"background-color:rgba(0, 0, 0, 0);color:#cf2e2e\" class=\"has-inline-color\">CNC machined components<\/mark><\/a>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">1. Linear Dimensional Tolerance (\u00b1mm)<\/h2>\n\n\n\n<p>This is the most basic but essential tolerance \u2014 controlling length, width, thickness, and diameter.<\/p>\n\n\n\n<p>In most industrial applications:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>General tolerance: \u00b10.05 mm to \u00b10.1 mm<\/li>\n\n\n\n<li>Precision assemblies: \u00b10.01 mm or tighter<\/li>\n<\/ul>\n\n\n\n<p>Improper control may cause:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Misalignment in assemblies<\/li>\n\n\n\n<li>Excessive vibration<\/li>\n\n\n\n<li>Increased bearing load<\/li>\n<\/ul>\n\n\n\n<p>For transmission and bearing-related components, tighter dimensional control is usually required.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">2. Diameter Tolerance for Shaft &amp; Bore Fits<\/h2>\n\n\n\n<p>Shaft and bore tolerances directly determine fit type:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Clearance fit<\/li>\n\n\n\n<li>Transition fit<\/li>\n\n\n\n<li>Interference fit<\/li>\n<\/ul>\n\n\n\n<p>Improper fit can result in:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Bearing creep<\/li>\n\n\n\n<li>Premature wear<\/li>\n\n\n\n<li>Assembly failure<\/li>\n<\/ul>\n\n\n\n<p>For rotating systems, ISO fit standards (e.g., H7\/g6, H7\/h6) are commonly applied.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">3. Concentricity<\/h2>\n\n\n\n<p>Concentricity ensures that multiple cylindrical features share the same axis.<\/p>\n\n\n\n<p>Critical for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Bearing housings<\/li>\n\n\n\n<li>\u56de\u8ee2\u30b7\u30e3\u30d5\u30c8<\/li>\n\n\n\n<li>Gear assemblies<\/li>\n<\/ul>\n\n\n\n<p>Poor concentricity leads to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Imbalance<\/li>\n\n\n\n<li>Noise<\/li>\n\n\n\n<li>Increased radial load<\/li>\n<\/ul>\n\n\n\n<p>In high-speed rotating equipment, this tolerance becomes extremely critical.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">4. Roundness (Circularity)<\/h2>\n\n\n\n<p>Roundness affects:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Seal contact performance<\/li>\n\n\n\n<li>Bearing load distribution<\/li>\n\n\n\n<li>Smooth rotation<\/li>\n<\/ul>\n\n\n\n<p>Even if diameter tolerance is acceptable, poor roundness may cause vibration or seal leakage.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">5. Flatness<\/h2>\n\n\n\n<p>Flatness is essential for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Sealing surfaces<\/li>\n\n\n\n<li>Mounting interfaces<\/li>\n\n\n\n<li>Mechanical contact areas<\/li>\n<\/ul>\n\n\n\n<p>Uneven surfaces may cause:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Oil leakage<\/li>\n\n\n\n<li>Uneven bolt load<\/li>\n\n\n\n<li>Structural stress concentration<\/li>\n<\/ul>\n\n\n\n<p>Flatness tolerance is especially important in sealing systems and hydraulic applications.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">6. Perpendicularity &amp; Parallelism<\/h2>\n\n\n\n<p>These geometric tolerances ensure proper alignment between surfaces.<\/p>\n\n\n\n<p>Applications:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Gear mounting<\/li>\n\n\n\n<li>Transmission assemblies<\/li>\n\n\n\n<li>Housing structures<\/li>\n<\/ul>\n\n\n\n<p>Poor perpendicularity can cause:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Gear tooth misalignment<\/li>\n\n\n\n<li>Uneven wear<\/li>\n\n\n\n<li>Increased mechanical stress<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">7. Surface Roughness (Ra Value)<\/h2>\n\n\n\n<p>Surface finish directly impacts:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Friction level<\/li>\n\n\n\n<li>Wear rate<\/li>\n\n\n\n<li>Seal performance<\/li>\n\n\n\n<li>Fatigue strength<\/li>\n<\/ul>\n\n\n\n<p>Typical ranges:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>General machining: Ra 3.2 \u2013 6.3 \u03bcm<\/li>\n\n\n\n<li>Sealing surface: Ra 0.4 \u2013 1.6 \u03bcm<\/li>\n\n\n\n<li>Bearing seat: Ra 0.8 \u2013 1.6 \u03bcm<\/li>\n<\/ul>\n\n\n\n<p>Over-finishing increases cost without added functional value.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">8. Position Tolerance<\/h2>\n\n\n\n<p>Position tolerance controls the exact location of holes, slots, or features relative to reference datums.<\/p>\n\n\n\n<p>Critical in:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Multi-hole mounting plates<\/li>\n\n\n\n<li>Transmission components<\/li>\n\n\n\n<li>Assembly-critical structures<\/li>\n<\/ul>\n\n\n\n<p>Incorrect positioning may lead to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Assembly interference<\/li>\n\n\n\n<li>Bolt stress concentration<\/li>\n\n\n\n<li>Reduced mechanical integrity<\/li>\n<\/ul>\n\n\n\n<h1 class=\"wp-block-heading\">Why Tolerance Control Matters in Industrial Applications<\/h1>\n\n\n\n<p>In industrial supply chains, tolerance control impacts:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Assembly efficiency<\/li>\n\n\n\n<li>\u30e1\u30f3\u30c6\u30ca\u30f3\u30b9\u983b\u5ea6<\/li>\n\n\n\n<li>Equipment downtime<\/li>\n\n\n\n<li>\u30e9\u30a4\u30d5\u30b5\u30a4\u30af\u30eb\u30b3\u30b9\u30c8<\/li>\n<\/ul>\n\n\n\n<p>Overly tight tolerances increase machining cost unnecessarily.<br>Too loose tolerances increase failure risk.<\/p>\n\n\n\n<p>The key is functional tolerance design \u2014 specifying precision only where performance requires it.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">How WONZH Supports Precision Machining Requirements<\/h1>\n\n\n\n<p>At WONZH, we focus on:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Machining according to customer drawings or samples<\/li>\n\n\n\n<li>Functional tolerance evaluation before production<\/li>\n\n\n\n<li>Inspection using calibrated measuring equipment<\/li>\n\n\n\n<li>Batch consistency control for replacement parts<\/li>\n<\/ul>\n\n\n\n<p>We support OEM replacement parts, transmission components, bearing-related parts, and industrial mechanical assemblies.<\/p>","protected":false},"excerpt":{"rendered":"<p>In industrial equipment and mechanical assemblies, dimensional tolerance is not just a drawing requirement \u2014 it directly affects assembly accuracy, operational stability, and long-term reliability. For OEM buyers and maintenance engineers, understanding which tolerances are truly critical can significantly reduce failure rates and unnecessary production costs. Below are 8 critical tolerances that must be properly controlled in custom CNC machined components. 1. Linear Dimensional Tolerance (\u00b1mm) This is the most basic but essential tolerance \u2014 controlling length, width, thickness, and diameter. In most industrial applications: Improper control may cause: For transmission and bearing-related components, tighter dimensional control is usually required. 2. Diameter Tolerance for Shaft &amp; Bore Fits Shaft and [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"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":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","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":"","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-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":"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":""},"mobile":{"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":""}},"footnotes":""},"categories":[28],"tags":[1796,477,1799,1791,1792,1800,1793,1794,1790,1795,756,1801,1798,1797],"class_list":["post-1997","post","type-post","status-publish","format-standard","hentry","category-technical-guides","tag-bearing-seat-machining","tag-cnc-machining","tag-concentricity-tolerance","tag-custom-cnc-parts","tag-dimensional-tolerance-control","tag-flatness-tolerance","tag-geometric-tolerances","tag-industrial-mechanical-parts","tag-machining-tolerances","tag-oem-machined-components","tag-precision-machining","tag-shaft-and-bore-fit","tag-surface-roughness-ra","tag-transmission-components-manufacturing"],"_links":{"self":[{"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/posts\/1997","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/comments?post=1997"}],"version-history":[{"count":1,"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/posts\/1997\/revisions"}],"predecessor-version":[{"id":1998,"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/posts\/1997\/revisions\/1998"}],"wp:attachment":[{"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/media?parent=1997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/categories?post=1997"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wonzh.com\/ja\/wp-json\/wp\/v2\/tags?post=1997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}