{"id":2235,"date":"2026-09-21T17:27:59","date_gmt":"2026-09-21T17:27:59","guid":{"rendered":"https:\/\/ychltools.com\/resources\/articles\/how-to-read-iso-turning-insert-codes\/"},"modified":"2026-10-14T08:11:17","modified_gmt":"2026-10-14T08:11:17","slug":"how-to-read-iso-turning-insert-codes","status":"publish","type":"page","link":"https:\/\/ychltools.com\/zh\/resources\/articles\/how-to-read-iso-turning-insert-codes\/","title":{"rendered":"How to Read ISO \u8f66\u524a\u5200\u7247 Codes: CNMG, WNMG, CCMT and More"},"content":{"rendered":"<style id=\"ychl-resources-v1\">\nbody:has(.ychl-resources-page) .wp-block-post-title{display:none!important}\nbody:has(.ychl-resources-page) main.wp-block-group,body:has(.ychl-resources-page) .wp-block-post-content{margin-block:0!important;max-width:none!important;padding-block:0!important;width:100%!important}\nbody:has(.ychl-resources-page) 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.ychl-article-lead{font-size:18px!important;line-height:1.7!important;margin-bottom:22px!important}\n.ychl-article-page .ychl-article-toc{border:0;display:flex;flex-wrap:wrap;gap:8px 16px;margin-top:13px;margin-bottom:27px;padding:6px 0}\n.ychl-article-page .ychl-article-toc strong{color:#183046;font-size:14px;white-space:nowrap}\n.ychl-article-page .ychl-article-toc a{font-size:14px;white-space:nowrap}\n.ychl-article-page>h2{border:0;font-size:27px;line-height:1.28;margin-top:44px;margin-bottom:18px;padding:0}\n.ychl-article-page>h3{font-size:20px;line-height:1.35;margin-top:31px;margin-bottom:11px}\n.ychl-article-page .ychl-article-table-wrap{margin-top:20px;margin-bottom:26px;max-width:920px;overflow-x:auto}\n.ychl-article-page .ychl-article-table-wrap table{font-size:15.5px;line-height:1.55;min-width:650px;width:100%}\n.ychl-article-page .ychl-article-table-wrap th{font-size:15px;padding:12px 14px}\n.ychl-article-page .ychl-article-table-wrap td{padding:13px 14px}\n.ychl-article-page .ychl-article-sources{border-top:1px solid #dce5eb;margin-top:42px;padding-top:21px}\n.ychl-article-page .ychl-article-sources h2{border:0;font-size:21px;margin:0 0 12px;padding:0}\n@media(max-width:767px){\n body:has(.ychl-article-page) .wp-block-post-content>.ychl-article-page{padding:20px 16px 44px!important}\n .ychl-article-page .ychl-resource-intro h1{font-size:clamp(34px,8vw,42px)}\n .ychl-article-page .ychl-resource-intro p{font-size:16px}\n .ychl-article-page>p,.ychl-article-page p,.ychl-article-page li{font-size:16.5px}\n .ychl-article-page>h2{font-size:24px;margin-top:38px}\n .ychl-article-page .ychl-article-toc a{white-space:normal}\n}\n\n\/* Keep prose and tables together at the lower end of the approved 860\u2013980px range. *\/\n.ychl-article-page>p,.ychl-article-page>ol,.ychl-article-page>h2,.ychl-article-page>h3,.ychl-article-page>.ychl-article-toc,.ychl-article-page>.ychl-article-sources{max-width:860px!important}\n.ychl-article-page>.ychl-article-table-wrap{max-width:860px!important}\n\n<\/style>\n<article class=\"ychl-resources-page ychl-article-page\"><div class=\"ychl-resource-crumb\"><a href=\"\/zh\/\">\u9996\u9875<\/a> \/ <a href=\"\/zh\/resources\/\">\u8d44\u6599\u4e2d\u5fc3<\/a> \/ <a href=\"\/zh\/resources\/articles\/\">\u6587\u7ae0<\/a><\/div><header class=\"ychl-resource-intro\"><h1>How to Read ISO \u8f66\u524a\u5200\u7247 Codes: CNMG, WNMG, CCMT and More<\/h1><p>Decode insert shape, clearance, tolerance, mounting style and size using three common turning examples. Learn which parts of a full model remain brand-specific.<\/p><\/header>\n<p class=\"ychl-article-lead\">An ISO insert designation tells you the basic geometry of an indexable insert. It does not, by itself, tell you that two brands use the same grade, chipbreaker, coating or cutting data. Read the standard designation first; then check the full manufacturer model and the holder seat before ordering.<\/p>\n<nav class=\"ychl-article-toc\" aria-label=\"On this page\"><strong>On this page:<\/strong><a href=\"#code-structure\">Code structure<\/a><a href=\"#three-examples\">Three examples<\/a><a href=\"#compare-shapes\">CNMG vs WNMG vs CCMT<\/a><a href=\"#before-ordering\">Before ordering<\/a><\/nav>\n\n<h2 id=\"code-structure\">The seven positions in the basic designation<\/h2>\n<p>Under ISO 1832, the familiar four letters and following size characters are read in order. The numbers are <em>designation codes<\/em>, not a promise that each printed number equals a dimension in millimetres. Confirm the actual dimensions from the manufacturer&#8217;s drawing.<\/p>\n<div class=\"ychl-article-table-wrap\"><table><thead><tr><th>Position<\/th><th>What it describes<\/th><th>What to check<\/th><\/tr><\/thead><tbody>\n<tr><td>1 \u2014 Shape<\/td><td>The insert outline, such as C (80\u00b0 rhombic) or W (80\u00b0 trigon).<\/td><td>Shape and seat must match the toolholder.<\/td><\/tr>\n<tr><td>2 \u2014 Clearance<\/td><td>The normal relief angle. N denotes 0\u00b0; C denotes 7\u00b0.<\/td><td>Do not confuse clearance with the working rake angle created by the holder and chipbreaker.<\/td><\/tr>\n<tr><td>3 \u2014 Tolerance<\/td><td>The dimensional tolerance class, such as M.<\/td><td>The class is not a carbide grade or workpiece material.<\/td><\/tr>\n<tr><td>4 \u2014 Insert type<\/td><td>The hole and chipbreaker arrangement. G and T identify different mounting\/face arrangements.<\/td><td>Check the maker&#8217;s drawing for the exact hole and seating geometry.<\/td><\/tr>\n<tr><td>5 \u2014 Size<\/td><td>A nominal size code interpreted together with the shape.<\/td><td>For these examples, CNMG 12 and WNMG 08 can both have a 12.70 mm inscribed circle.<\/td><\/tr>\n<tr><td>6 \u2014 \u539a\u5ea6<\/td><td>A thickness code, such as 04 or T3.<\/td><td>Examples below use 04 = 4.76 mm and T3 = 3.97 mm; verify the actual item.<\/td><\/tr>\n<tr><td>7 \u2014 Corner radius<\/td><td>The nose-radius code. In the examples below, 08 = 0.8 mm and 04 = 0.4 mm.<\/td><td>Changing radius can change the finish, edge strength and programming offset.<\/td><\/tr>\n<\/tbody><\/table><\/div>\n\n<h2 id=\"three-examples\">Read three common models, one position at a time<\/h2>\n<h3>CNMG 120408<\/h3>\n<p><strong>C<\/strong> is an 80\u00b0 rhombic shape; <strong>N<\/strong> is 0\u00b0 normal clearance; <strong>M<\/strong> is the tolerance class; <strong>G<\/strong> specifies a cylindrical fixing hole and chipbreaker features on both faces in this designation. The <strong>12<\/strong> size corresponds to a 12.70 mm inscribed circle in the catalogued example. <strong>04<\/strong> denotes 4.76 mm thickness, and the final <strong>08<\/strong> denotes a 0.8 mm nose radius.<\/p>\n<p>CNMG is a common negative-clearance, double-sided insert format for general turning. The complete saleable SKU still needs the maker&#8217;s chipbreaker and grade designation; \u201cCNMG 120408\u201d alone is not enough to choose an exact cutting edge.<\/p>\n\n<h3>WNMG 080408<\/h3>\n<p><strong>W<\/strong> is an 80\u00b0 trigon; <strong>N<\/strong> is 0\u00b0 normal clearance; <strong>M<\/strong> is the tolerance class; <strong>G<\/strong> denotes the cylindrical hole and double-face chipbreaker arrangement. For this W shape, size code <strong>08<\/strong> corresponds to a 12.70 mm inscribed circle in the catalogued example\u2014another reason not to treat the printed size code as a direct millimetre measurement. <strong>04<\/strong> denotes 4.76 mm thickness; the final <strong>08<\/strong> is a 0.8 mm nose radius.<\/p>\n<p>The W outline offers three corners on each face in the usual double-sided format. It is not interchangeable with a CNMG insert merely because both examples have the same inscribed-circle diameter; the seat geometry differs.<\/p>\n\n<h3>CCMT 09T304<\/h3>\n<p><strong>C<\/strong> is an 80\u00b0 rhombic shape; the second <strong>C<\/strong> denotes 7\u00b0 normal clearance; <strong>M<\/strong> is the tolerance class; <strong>T<\/strong> specifies a countersunk fixing-hole arrangement with chipbreaker features on one face. Size <strong>09<\/strong> corresponds to a 9.52 mm inscribed circle in the catalogued example. <strong>T3<\/strong> denotes 3.97 mm thickness and the final <strong>04<\/strong> denotes a 0.4 mm nose radius.<\/p>\n<p>CCMT is a positive-clearance insert format. \u5bf9\u6bd4d with the zero-clearance examples above, the insert and holder combination may be useful where a lighter cutting action is needed. Confirm holder compatibility and choose a manufacturer-specific geometry for the actual cut.<\/p>\n\n<h2 id=\"compare-shapes\">CNMG vs WNMG vs CCMT: where to start<\/h2>\n<div class=\"ychl-article-table-wrap\"><table><thead><tr><th>Family<\/th><th>Basic geometry<\/th><th>Practical starting point<\/th><\/tr><\/thead><tbody>\n<tr><td><a href=\"\/zh\/turning-inserts\/cnmg\/\">CNMG<\/a><\/td><td>80\u00b0 rhombic, 0\u00b0 normal clearance, commonly double-sided.<\/td><td>General turning where the holder and workpiece clearance suit this shape.<\/td><\/tr>\n<tr><td><a href=\"\/zh\/turning-inserts\/wnmg\/\">WNMG<\/a><\/td><td>80\u00b0 trigon, 0\u00b0 normal clearance, commonly double-sided.<\/td><td>General turning when a W-style seat and its available corners suit the job.<\/td><\/tr>\n<tr><td><a href=\"\/zh\/product-search\/?q=CCMT\">CCMT<\/a><\/td><td>80\u00b0 rhombic, 7\u00b0 normal clearance, one-face T-type configuration.<\/td><td>Lighter-cutting or internal-turning setups where a compatible positive-clearance insert is specified.<\/td><\/tr>\n<\/tbody><\/table><\/div>\n<p>These are starting points, not a ranking. The holder, approach angle, available clearance, workpiece material and machining stage all matter. A grade or chipbreaker code such as a maker&#8217;s finishing or medium geometry is <strong>not<\/strong> standardised across brands by the seven-position ISO designation.<\/p>\n\n<h2 id=\"before-ordering\">What to confirm before ordering<\/h2>\n<ol><li>Record the complete model printed on the pack or insert, including any suffix and grade.<\/li><li>Check shape, clearance, size, thickness, radius and fixing hole against the toolholder&#8217;s insert specification.<\/li><li>Specify the workpiece material and whether the cut is finishing, medium or roughing.<\/li><li>\u5bf9\u6bd4 the brand&#8217;s available chipbreakers and grades for those conditions.<\/li><li>If replacing another brand, send the current model or a clear photo rather than assuming that similar letters mean a direct substitute.<\/li><\/ol>\n<p><a href=\"\/zh\/turning-inserts\/\">\u6d4f\u89c8 turning \u5200\u7247 \u2192<\/a> &nbsp; <a href=\"\/zh\/help-me-choose\/\">Ask for selection help \u2192<\/a><\/p>\n<div class=\"ychl-article-sources\"><h2>Technical references<\/h2><p><a href=\"https:\/\/www.iso.org\/standard\/69202.html\" target=\"_blank\" rel=\"noopener noreferrer\">ISO 1832:2017 \u2014 Indexable \u5200\u7247 for cutting tools \u2014 Designation<\/a>; <a href=\"https:\/\/epublications.sandvik.coromant.com\/frontend\/catalogs\/1249041\/1\/pdf\/complete.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Sandvik Coromant catalogue dimensions for CNMG and CCMT examples<\/a>; <a href=\"https:\/\/epublications.sandvik.coromant.com\/frontend\/catalogs\/1098482\/1\/pdf\/complete.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Sandvik Coromant catalogue dimensions for WNMG examples<\/a>. Check the current manufacturer&#8217;s product sheet for the item you intend to order.<\/p><\/div>\n<\/article>\n\n\n<div class=\"ychl-tool-promo\" style=\"border:1px solid #dfe6ec;border-radius:10px;padding:18px 22px;background:#fafcfe;margin-top:28px;\">\n  <h3>Try the ISO insert code decoder<\/h3>\n  <p>Enter any ISO designation \u2014 such as CNMG 120408 or CCMT 09T304 \u2014 and instantly see the shape, clearance angle, tolerance, hole\/chipbreaker layout and the exact dimensions stocked by YCHL.<\/p>\n  <a href=\"\/zh\/resources\/iso-insert-code-decoder\/\" style=\"display:inline-block;padding:11px 18px;border-radius:8px;background:#0877a4;color:#fff;text-decoration:none;font-weight:600;\">Open the ISO decoder<\/a>\n<\/div>\n<h2>Related guides<\/h2>\n<ul>\n<li><a href=\"\/zh\/resources\/turning-insert-selection-guide\/\">How to choose a turning insert<\/a><\/li>\n<li><a href=\"\/zh\/resources\/carbide-grades-explained\/\">Carbide grades explained<\/a><\/li>\n<li><a href=\"\/zh\/resources\/chipbreaker-selection-guide\/\">\u69fd\u578b and geometry selection<\/a><\/li>\n<li><a href=\"\/zh\/resources\/cutting-parameters-calculator\/\">Cutting speed \/ feed calculator<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Home \/ Resources \/ Articles How to Read ISO Turning Insert Codes: CNMG, WNMG, CCMT and More Decode insert shape, clearance, tolerance, mounting style and size using three common turning examples. Learn which parts of a full model remain brand-specific. An ISO insert designation tells you the basic geometry of an indexable insert. It does [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2234,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":"","_ychl_meta_desc":"","_ychl_model_html":""},"class_list":["post-2235","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages\/2235","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/comments?post=2235"}],"version-history":[{"count":5,"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages\/2235\/revisions"}],"predecessor-version":[{"id":10742,"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages\/2235\/revisions\/10742"}],"up":[{"embeddable":true,"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages\/2234"}],"wp:attachment":[{"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/media?parent=2235"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}