{"id":9438,"date":"2021-12-22T16:49:31","date_gmt":"2021-12-22T14:49:31","guid":{"rendered":"https:\/\/info.formfedern.com\/bending-radius-in-metal-forming\/"},"modified":"2021-12-22T16:49:41","modified_gmt":"2021-12-22T14:49:41","slug":"bending-radius-in-metal-forming","status":"publish","type":"post","link":"https:\/\/info.formfedern.com\/en\/bending-radius-in-metal-forming\/","title":{"rendered":"Bending radius in metal forming"},"content":{"rendered":"<p>The bending radius (r) is the radius measured after the <a href=\"https:\/\/info.formfedern.com\/biegeverfahren-metallumformung\/\">bending process of<\/a> a metal component or a <a href=\"https:\/\/info.formfedern.com\/formfedern-flachfedern-blattfedern\/\">shaped spring<\/a> and <a href=\"https:\/\/info.formfedern.com\/flachformfeder_auslegen\/\">flat shaped spring<\/a>. However, the <a href=\"https:\/\/info.formfedern.com\/federstahlbleche-eigenschaften\/\">strength of the spring material<\/a> decreases due to bending. The material thickness at the bending point is also reduced.<\/p>\n<p><a href=\"https:\/\/info.formfedern.com\/wp-content\/uploads\/Biegeradius_Grafik.jpg\" target=\"_blank\" rel=\"noopener noreferrer\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-9439\" src=\"https:\/\/info.formfedern.com\/wp-content\/uploads\/\/Biegeradius_Grafik-300x225.jpg\" alt=\"Bending radius metal forming - Gutekunst form springs\" width=\"400\" height=\"300\" data-wp-pid=\"2440\" srcset=\"https:\/\/info.formfedern.com\/wp-content\/uploads\/Biegeradius_Grafik-300x225.jpg 300w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Biegeradius_Grafik-768x576.jpg 768w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Biegeradius_Grafik-600x450.jpg 600w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Biegeradius_Grafik-200x150.jpg 200w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Biegeradius_Grafik.jpg 800w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/a><\/p>\n<ul>\n<li>\u03b1 = bending angle<\/li>\n<li>\u03b2 = opening angle<\/li>\n<li>L = material length<\/li>\n<li>r = bending radius<\/li>\n<li>s = spring steel plate thickness<\/li>\n<\/ul>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/info.formfedern.com\/en\/bending-radius-in-metal-forming\/#The_bending_process_in_detail\" >The bending process in detail:<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/info.formfedern.com\/en\/bending-radius-in-metal-forming\/#How_do_you_determine_the_minimum_bending_radius\" >How do you determine the minimum bending radius?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/info.formfedern.com\/en\/bending-radius-in-metal-forming\/#What_should_be_considered_when_bending\" >What should be considered when bending?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/info.formfedern.com\/en\/bending-radius-in-metal-forming\/#Spring_design_of_Gutekunst_Formfedern\" >Spring design of Gutekunst Formfedern<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"The_bending_process_in_detail\"><\/span>The bending process in detail:<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>During <a href=\"https:\/\/info.formfedern.com\/biegeverfahren-metallumformung\/\">bending forming<\/a>, the outer fiber or exterior (marked red in the figure) of the <a href=\"https:\/\/info.formfedern.com\/formfedern-flachfedern-blattfedern\/\">forming spring<\/a>, <a href=\"https:\/\/info.formfedern.com\/flachformfeder-berechnung\/\">flat forming spring<\/a> or <a href=\"https:\/\/info.formfedern.com\/stanzteile-kleinserien\/\">metal component<\/a> is stretched. The inner fiber (blue, stands for inside), on the other hand, is compressed. Between the outer and the inner fiber lies the neutral fiber (green). This area is neither stretched nor compressed.<\/p>\n<p>In order to exclude a reduction in quality due to compression and stretching, it is important to maintain minimum bending radii. This is the smallest possible bending radius of a material at which the workpiece does not break. If this value is undershot, cracks will appear on the outside and bruising on the inside. In addition, the cross-section in the bending zone can change. This means that there is a risk of the workpiece breaking.<\/p>\n<p><span style=\"text-decoration: underline;\">Generally, therefore<\/span>:<\/p>\n<ul>\n<li>larger bending radius = lower risk of breakage and reduction in strength<\/li>\n<\/ul>\n<ul>\n<li>smaller bending radius = greater risk of breakage due to thinner material thickness at bending point<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"How_do_you_determine_the_minimum_bending_radius\"><\/span>How do you determine the minimum bending radius?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Each <a href=\"https:\/\/info.formfedern.com\/federstahlbleche-eigenschaften\/\">spring material<\/a> has its own minimum bending radius. This depends on the composition of the alloy, the material thickness and the <a href=\"https:\/\/de.wikipedia.org\/wiki\/Streckgrenze\" target=\"_blank\" rel=\"noopener noreferrer\">yield<\/a> strength <a href=\"https:\/\/de.wikipedia.org\/wiki\/Streckgrenze\" target=\"{wpml_trans_unit_1_0_40_-1_1}\" rel=\"{wpml_trans_unit_1_0_40_-1_2} noopener noreferrer\">ratio<\/a>. This is the ratio of the <a href=\"https:\/\/info.formfedern.com\/spannungs-dehnungs-diagramm\/\" target=\"_blank\" rel=\"noopener noreferrer\">yield strength or elastic limit<\/a> (Rp) to the <a href=\"https:\/\/info.formfedern.com\/federstahlbleche-eigenschaften\/\">tensile strength<\/a> (Rm) of the material. For spring steel grades, this is usually over 85 percent. In comparison, the yield strength ratio of structural steel is only about 40 percent &#8211; lower values are also conceivable.<\/p>\n<p>In order to determine the minimum bending radius, various factors must be taken into account. The following is an overview of the most important sizes:<\/p>\n<ul>\n<li><a href=\"https:\/\/info.formfedern.com\/federstahlbleche-eigenschaften\/\" target=\"_blank\" rel=\"noopener noreferrer\">Spring steel type<\/a><\/li>\n<li>Spring steel thickness<\/li>\n<li><a href=\"https:\/\/info.formfedern.com\/federstahlbleche-eigenschaften\/\" target=\"_blank\" rel=\"noopener noreferrer\">tensile strenght<\/a><\/li>\n<li><a href=\"https:\/\/info.formfedern.com\/biegeverfahren-metallumformung\/\" target=\"_blank\" rel=\"noopener noreferrer\">Bending method<\/a><\/li>\n<li>Bending tools<\/li>\n<li>Bending speed<\/li>\n<li>Rolling direction of the spring steel<\/li>\n<li>Pressing force<\/li>\n<\/ul>\n<p>Elasticity is considered to be one of the main characteristics of spring steel. It is achieved in the manufacturing process by adding silicon (Si), manganese (Mn), chromium (Cr), vanadium (V), molybdenum (Mo) and nickel (Ni) to a special alloy. As a general rule, the <a href=\"https:\/\/blog.federnshop.com\/elastizitaetsmodul\/\" target=\"_blank\" rel=\"noopener noreferrer\">elasticity of<\/a> <a href=\"https:\/\/info.formfedern.com\/federstahlbleche-eigenschaften\/\" target=\"_blank\" rel=\"noopener noreferrer\">spring steels<\/a> with higher tensile strength is lower than that of <a href=\"https:\/\/info.formfedern.com\/federstahlbleche-eigenschaften\/\" target=\"{wpml_trans_unit_1_0_57_-1_1}\" rel=\"{wpml_trans_unit_1_0_57_-1_2} noopener noreferrer\">steels<\/a> with lower tensile strength. For materials with higher tensile strength, the minimum bending radius must therefore be set larger.<\/p>\n<p>For the different types of spring steel such as the normal  <a href=\"https:\/\/info.formfedern.com\/federbandstahl-ab-lager\/\" target=\"_blank\" rel=\"noopener noreferrer\">Spring steel plate C75S<\/a>, the corrosion-resistant  <a href=\"https:\/\/info.formfedern.com\/federbandstahl-c75-und-1-4310\/\" target=\"_blank\" rel=\"noopener noreferrer\">Stainless steel grades 1.4310<\/a>, 1.4568 and 1.4401, the non-magnetic spring bronze CuSn6 and the copper-beryllium spring steel CuB2 as well as the heat-resistant spring steels Nimonic 90, Inconel X-750 and 718, the exact minimum bending radii for  <a href=\"https:\/\/info.formfedern.com\/gutekunst-stahlverformung\/\" target=\"_blank\" rel=\"noopener noreferrer\">Gutekunst Formfedern<\/a> described and determined and managed in test bends.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"What_should_be_considered_when_bending\"><\/span>What should be considered when bending?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure id=\"attachment_9440\" aria-describedby=\"caption-attachment-9440\" style=\"width: 380px\" class=\"wp-caption alignleft\"><a href=\"https:\/\/info.formfedern.com\/wp-content\/uploads\/Mindestbiegeradius_800.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-9440\" src=\"https:\/\/info.formfedern.com\/wp-content\/uploads\/\/Mindestbiegeradius_800-300x210.jpg\" alt=\"Minimum bending radius according to rolling direction - Gutekunst Formfedern\" width=\"380\" height=\"266\" data-wp-pid=\"3729\" srcset=\"https:\/\/info.formfedern.com\/wp-content\/uploads\/Mindestbiegeradius_800-300x210.jpg 300w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Mindestbiegeradius_800-768x539.jpg 768w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Mindestbiegeradius_800-600x421.jpg 600w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Mindestbiegeradius_800-150x105.jpg 150w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Mindestbiegeradius_800-285x200.jpg 285w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Mindestbiegeradius_800-200x140.jpg 200w, https:\/\/info.formfedern.com\/wp-content\/uploads\/Mindestbiegeradius_800.jpg 800w\" sizes=\"auto, (max-width: 380px) 100vw, 380px\" \/><\/a><figcaption id=\"caption-attachment-9440\" class=\"wp-caption-text\">\u00a9 SBS Special machines<\/figcaption><\/figure>\n<p>An important factor in <a href=\"https:\/\/info.formfedern.com\/biegeverfahren-metallumformung\/\" target=\"_blank\" rel=\"noopener noreferrer\">bending forming<\/a> is, among other things, the rolling direction of the spring steel sheet. This is because the stretching of the material during rolling creates a fibrous material structure. The elongation of the fibres always occurs in the rolling direction. If the steel sheet is bent along the rolling direction, it may break prematurely. The minimum bending radius must be larger in such a case. If, on the other hand, the workpiece &#8211; such as a <a href=\"https:\/\/info.formfedern.com\/formfedern-flachfedern-blattfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">shaped spring<\/a>, <a href=\"https:\/\/info.formfedern.com\/flachformfeder_auslegen\/\" target=\"_blank\" rel=\"noopener noreferrer\">flat shaped spring<\/a> or <a href=\"https:\/\/info.formfedern.com\/stanzteile-kleinserien\/\" target=\"_blank\" rel=\"noopener noreferrer\">metal component<\/a> &#8211; is bent transversely to the rolling direction, a smaller minimum bending radius is possible.<\/p>\n<p>In addition, the determination of the required pressing force also plays an important role in bending. In order to permanently reshape the spring steel, the value of the <a href=\"https:\/\/info.formfedern.com\/spannungs-dehnungs-diagramm\/\" target=\"_blank\" rel=\"noopener noreferrer\">yield strength<\/a> must be exceeded. If this is not the case, the metal returns to its original state. Only a load above the yield point causes plastic deformation. It is essential to ensure that the <a href=\"https:\/\/info.formfedern.com\/federstahlbleche-eigenschaften\/\" target=\"_blank\" rel=\"noopener noreferrer\">tensile strength of the spring material<\/a> is not exceeded, otherwise the material could be damaged.<\/p>\n<p>To ensure that the material does not tear or even form crimp folds, especially with thicker material and small bending radii, it is necessary to have a wide range of different tools available for the various bending radii.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Spring_design_of_Gutekunst_Formfedern\"><\/span>Spring design of Gutekunst Formfedern<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>With <a href=\"https:\/\/info.formfedern.com\/gutekunst-stahlverformung\/\" target=\"_blank\" rel=\"noopener noreferrer\">Gutekunst Formfedern<\/a> you do not have to worry about such possible problems. This is because Gutekunst develops the right <a href=\"https:\/\/info.formfedern.com\/flachformfeder_auslegen\/\" target=\"_blank\" rel=\"noopener noreferrer\">flat form springs<\/a> or <a href=\"https:\/\/info.formfedern.com\/flachformfeder-berechnung\/\" target=\"_blank\" rel=\"noopener noreferrer\">form springs<\/a> together with you right from the start.<\/p>\n<p>If you are interested, simply send us your application for a flat shaped spring or shaped spring with the desired properties via our <a href=\"https:\/\/info.formfedern.com\/formfedern-anfrage\/\" target=\"_blank\" rel=\"noopener noreferrer\">enquiry button shaped springs<\/a> or to <a href=\"mailto:info@gutekunst-formfedern.de\">info@gutekunst-formfedern.de<\/a>.<\/p>\n<p style=\"text-align: left;\"><a class=\"maxbutton-1 maxbutton maxbutton-formfedern\" target=\"_blank\" rel=\"noopener\" href=\"https:\/\/info.formfedern.com\/formfedern-anfrage\/\"><span class='mb-text'>Anfrage Formfedern &amp; Blattfedern<\/span><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><em>Further information can also be found here:<\/em><\/p>\n<ul>\n<li><a href=\"https:\/\/info.formfedern.com\/lasern-stanzen-umformen\/\">Lasering, punching, forming and assembling<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/info.formfedern.com\/biegeverfahren-metallumformung\/\">Bending process in metal forming<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/info.formfedern.com\/flachformfeder_auslegen\/\">Lay out flat spring<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/info.formfedern.com\/flachformfeder-berechnung\/\">Flat shape spring calculation<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/info.formfedern.com\/federclips\/\">Spring clips for every application<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/info.formfedern.com\/federstahlklammer\/\">Spring steel clips galvanized and made of stainless steel<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/info.formfedern.com\/laserteile-bestellen\/\">Order laser parts quickly and easily<\/a><\/li>\n<\/ul>\n<p>&nbsp;<\/p>","protected":false},"excerpt":{"rendered":"<p>The bending radius (r) is the radius measured after the bending process of a metal component or a shaped spring and flat shaped spring. However, the strength of the spring material decreases due to bending. The material thickness at the<\/p>\n","protected":false},"author":6,"featured_media":9439,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[701,710],"tags":[3078,3079,3048,937,3076,3075,3077,1045,2507,3015,3080],"class_list":["post-9438","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-knowledge","category-shaped-springs","tag-bending","tag-bending-en","tag-bending-radius","tag-edelstahl-en","tag-elastic-limit","tag-minimum-bending-radius","tag-sheet-steel","tag-spring-steel","tag-tensile-strenght","tag-yield-strength","tag-yield-strength-ratio"],"_links":{"self":[{"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/posts\/9438","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/comments?post=9438"}],"version-history":[{"count":1,"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/posts\/9438\/revisions"}],"predecessor-version":[{"id":9441,"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/posts\/9438\/revisions\/9441"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/media\/9439"}],"wp:attachment":[{"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/media?parent=9438"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/categories?post=9438"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/info.formfedern.com\/en\/wp-json\/wp\/v2\/tags?post=9438"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}