{"id":10728,"date":"2026-10-14T07:25:21","date_gmt":"2026-10-14T07:25:21","guid":{"rendered":"https:\/\/ychltools.com\/resources\/hardened-steel-turning-inserts\/"},"modified":"2026-10-21T15:01:56","modified_gmt":"2026-10-21T15:01:56","slug":"hardened-steel-turning-inserts","status":"publish","type":"page","link":"https:\/\/ychltools.com\/zh\/resources\/hardened-steel-turning-inserts\/","title":{"rendered":"Hard Turning and \u5200\u7247 for \u6dec\u786c\u94a2 (ISO H)"},"content":{"rendered":"<p>Above roughly 45 HRC, conventional carbide stops working: the edge deforms plastically within seconds. Two options remain \u2014 <strong>hard turning with a dedicated H-group carbide<\/strong>, or <strong>CBN (cubic boron nitride)<\/strong>. Hard turning is cheaper and more flexible; CBN is faster and holds tighter tolerances in volume.<\/p>\n<h2>Real cutting data for ISO H<\/h2>\n<p>Aggregated from 156 insert records published for hardened steel in our catalogue:<\/p>\n<div class=\"ychl-art-table\">\n<table>\n<thead>\n<tr>\n<th>Parameter<\/th>\n<th>Full published range<\/th>\n<th>Typical (median)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Cutting speed vc<\/td>\n<td>90 \u2013 180 m\/min<\/td>\n<td><strong>120 \u2013 180 m\/min<\/strong><\/td>\n<\/tr>\n<tr>\n<td>Feed fn<\/td>\n<td>0.03 \u2013 0.30 mm\/rev<\/td>\n<td><strong>shallow, low feed<\/strong><\/td>\n<\/tr>\n<tr>\n<td>Depth of cut ap<\/td>\n<td>\u2014<\/td>\n<td><strong>shallow (usually 0.05 \u2013 0.5 mm)<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Note how narrow the window is. Hard turning is not &#8220;turning with a harder insert&#8221; \u2014 it is a different process with a much smaller parameter box.<\/p>\n<h2>\u724c\u53f7s that work<\/h2>\n<p>Our hardened-steel grades: <strong>PB30, PB60, AP153H, AP151H<\/strong>.<\/p>\n<p>These are fine-grain substrates with thin PVD coatings and a <strong>honed (T-land) edge<\/strong>. The hone is not optional: a sharp edge in hardened steel chips instantly. The edge preparation does the work.<\/p>\n<h2>Setup requirements \u2014 this is what decides success<\/h2>\n<p>Most hard-turning failures are machine problems, not tool problems. Before you start:<\/p>\n<ul>\n<li><strong>Rigidity.<\/strong> Anything that deflects will chatter and destroy the edge. Short overhang, solid workholding, no slop in the tool post or turret.<\/li>\n<li><strong>Spindle condition.<\/strong> Runout directly translates to uneven edge load.<\/li>\n<li><strong>Negative geometry.<\/strong> Always. The insert needs the included angle behind the edge.<\/li>\n<li><strong>Large nose radius where possible<\/strong> \u2014 it supports the edge and improves finish, at the cost of higher radial force.<\/li>\n<li><strong>Dry cutting.<\/strong> Coolant thermally shocks the edge in this process. Some use a light air blast.<\/li>\n<\/ul>\n<p>If your setup cannot meet these, hard turning will not work no matter which grade you buy. Grind instead.<\/p>\n<h2>Hard turning versus grinding<\/h2>\n<div class=\"ychl-art-table\">\n<table>\n<thead>\n<tr>\n<th><\/th>\n<th>Hard turning<\/th>\n<th>Grinding<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Setup \/ changeover<\/td>\n<td>Fast, one setup for multiple diameters<\/td>\n<td>Slower<\/td>\n<\/tr>\n<tr>\n<td>\u52a0\u5de5\u6750\u6599 removal rate<\/td>\n<td>Higher in roughing<\/td>\n<td>Lower<\/td>\n<\/tr>\n<tr>\n<td>Dimensional accuracy<\/td>\n<td>IT6\u2013IT7 typical<\/td>\n<td>IT5 and better<\/td>\n<\/tr>\n<tr>\n<td>Surface finish<\/td>\n<td>Ra 0.2\u20130.8 achievable<\/td>\n<td>Better, and more consistent<\/td>\n<\/tr>\n<tr>\n<td>Geometry flexibility<\/td>\n<td>High \u2014 contours, threads, grooves in one setup<\/td>\n<td>Limited by wheel<\/td>\n<\/tr>\n<tr>\n<td>Cost per part<\/td>\n<td>Lower at low\u2013medium volume<\/td>\n<td>Lower at very high volume<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>The common practical answer: rough and semi-finish by hard turning, then either finish by turning (if the tolerance allows) or grind only the critical features.<\/p>\n<h2>Failure modes<\/h2>\n<ul>\n<li><strong>Plastic deformation of the edge<\/strong> \u2014 vc or fn too high. Lower both, use a harder grade.<\/li>\n<li><strong>Chipping at the edge<\/strong> \u2014 setup not rigid, or hone too light. Increase nose radius, check runout.<\/li>\n<li><strong>Rapid flank wear<\/strong> \u2014 normal in hard turning; expect short tool life and plan for it.<\/li>\n<li><strong>Thermal cracking<\/strong> \u2014 you used coolant. \u8df3\u8f6c dry.<\/li>\n<\/ul>\n<h2>Related<\/h2>\n<ul>\n<li><a href=\"\/zh\/resources\/iso-513-material-groups\/\">ISO 513 material groups explained<\/a><\/li>\n<li><a href=\"\/zh\/resources\/carbide-grades-explained\/\">Carbide grades explained<\/a><\/li>\n<li><a href=\"\/zh\/resources\/turning-insert-selection-guide\/\">Turning insert selection guide<\/a><\/li>\n<li><a href=\"\/zh\/resources\/cutting-parameters-calculator\/\">Cutting parameters calculator<\/a><\/li>\n<\/ul>\n<h2>Standards and further reading<\/h2>\n<p>The material group definitions used throughout this site follow ISO 513. The manufacturer links below are independent technical references.<\/p>\n<ul>\n<li><a href=\"https:\/\/www.iso.org\/standard\/59932.html\" rel=\"noopener\" target=\"_blank\">ISO 513:2012 \u2013 \u52a0\u5de5\u6750\u6599 group definitions<\/a><\/li>\n<li><a href=\"https:\/\/www.sandvik.coromant.com\/en-gb\/knowledge\/materials\" rel=\"nofollow noopener\" target=\"_blank\">Sandvik Coromant \u2013 \u6750\u6599 knowledge<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Above roughly 45 HRC, conventional carbide stops working: the edge deforms plastically within seconds. Two options remain \u2014 hard turning with a dedicated H-group carbide, or CBN (cubic boron nitride). Hard turning is cheaper and more flexible; CBN is faster and holds tighter tolerances in volume. Real cutting data for ISO H Aggregated from 156 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":2220,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":"","_ychl_meta_desc":"When to hard turn instead of grind: real cutting data above 45 HRC, which grades and geometries survive, and the setup that decides success.","_ychl_model_html":""},"class_list":["post-10728","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages\/10728","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=10728"}],"version-history":[{"count":1,"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages\/10728\/revisions"}],"predecessor-version":[{"id":10739,"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages\/10728\/revisions\/10739"}],"up":[{"embeddable":true,"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/pages\/2220"}],"wp:attachment":[{"href":"https:\/\/ychltools.com\/zh\/wp-json\/wp\/v2\/media?parent=10728"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}