{"id":6713,"date":"2021-01-27T17:48:20","date_gmt":"2021-01-27T15:48:20","guid":{"rendered":"https:\/\/blog.federnshop.com\/design-of-metal-springs-part-2-calculation\/"},"modified":"2024-04-25T11:34:45","modified_gmt":"2024-04-25T09:34:45","slug":"design-of-metal-springs-part-2-calculation","status":"publish","type":"post","link":"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/","title":{"rendered":"Design of metal springs &#8211; Part 2 &#8220;Calculation"},"content":{"rendered":"<p>In the <a href=\"https:\/\/blog.federnshop.com\/auslegung-metallfedern-grundlagen\/\" target=\"_blank\" rel=\"noopener\">first part<\/a> of this two-part series <a href=\"https:\/\/blog.federnshop.com\/gutekunst-federn\/\" target=\"_blank\" rel=\"noopener noreferrer\">Gutekunst Federn<\/a> informed about the <a href=\"https:\/\/blog.federnshop.com\/auslegung-metallfedern-grundlagen\/\" target=\"_blank\" rel=\"noopener noreferrer\">basics of spring design<\/a>. In this second part you will find the concrete calculation data for the design of <a href=\"https:\/\/blog.federnshop.com\/druckfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">compression springs<\/a>, <a href=\"https:\/\/blog.federnshop.com\/zugfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">extension<\/a> springs and <a href=\"https:\/\/blog.federnshop.com\/schenkelfedern-torsionsfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">torsion springs<\/a> (torsion springs). The <a href=\"https:\/\/www.federnshop.com\/de\/service-und-informationen\/federberechnung-nach-din-13906.html\" target=\"_blank\" rel=\"noopener noreferrer\">Gutekunst spring calculation program WinFSB<\/a> is also available for individual Gutekunst spring calculation program WinFSB.<\/p>\n<p>The aim of the spring design of a compression spring, tension spring or torsion spring is to find the most economical spring for the given task, taking into account all circumstances, which also fits into the available space and achieves the required <a href=\"https:\/\/blog.federnshop.com\/dauerfestigkeit\/\" target=\"_blank\" rel=\"noopener noreferrer\">service life<\/a>. In addition to these manufacturing and <a title=\"Spring steel wires and their properties\" href=\"https:\/\/blog.federnshop.com\/federstahldraht\/\" target=\"_blank\" rel=\"noopener\">material requirements<\/a>, the correct <a href=\"https:\/\/blog.federnshop.com\/federauslegung\/\" target=\"_blank\" rel=\"noopener noreferrer\">spring design<\/a> is of particular importance.<\/p>\n<p><strong>Before calculating the spring, the following requirements of the metal spring should be compiled:<\/strong><\/p>\n<p><strong>1.<\/strong> <a href=\"https:\/\/blog.federnshop.com\/beanspruchung-druckfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">type of load<\/a> (static or dynamic)<\/p>\n<p><strong>2.<\/strong> <a title=\"Fatigue strength\" href=\"https:\/\/blog.federnshop.com\/dauerfestigkeit\/\" target=\"_blank\" rel=\"noopener\">Lifetime<\/a><\/p>\n<p><strong>3.<\/strong> <a href=\"https:\/\/blog.federnshop.com\/federwerkstoffe-arbeitstemperatur\/\" target=\"_blank\" rel=\"noopener noreferrer\">Operating temperature<\/a><\/p>\n<p><strong>4. <\/strong> <a href=\"https:\/\/blog.federnshop.com\/federstahl\/\" target=\"_blank\" rel=\"noopener\">Ambient medium<\/a><\/p>\n<p><strong>5.<\/strong> <a href=\"https:\/\/blog.federnshop.com\/federkraft-berechnen\/\" target=\"_blank\" rel=\"noopener noreferrer\">Required forces and spring deflections<\/a><\/p>\n<p><strong>6.<\/strong> available installation space<\/p>\n<p><strong>7.<\/strong> tolerances<a href=\"https:\/\/blog.federnshop.com\/toleranzen-druckfedern\/\" target=\"_blank\" rel=\"noopener\">(compression springs<\/a>, <a href=\"https:\/\/blog.federnshop.com\/toleranzen-zugfedern\/\" target=\"_blank\" rel=\"noopener\">tension springs<\/a>)<\/p>\n<p><strong>8.<\/strong> <a href=\"https:\/\/blog.federnshop.com\/auslegung-metallfedern-grundlagen\/\" target=\"_blank\" rel=\"noopener noreferrer\">installation situation<\/a> (buckling, transverse suspension)<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Each spring calculation consists of two stages:<\/strong><\/p>\n<ul>\n<li><strong><a href=\"https:\/\/blog.federnshop.com\/funktions-festigkeitsnachweis\/\" target=\"_blank\" rel=\"noopener noreferrer\">Functional verification<\/a><\/strong>: Checking the spring rate, the forces and the spring travel, the vibration behaviour, etc.<\/li>\n<li><a href=\"https:\/\/blog.federnshop.com\/funktions-festigkeitsnachweis\/\" target=\"_blank\" rel=\"noopener noreferrer\"><strong>Strength verification<\/strong><br \/>\n<\/a>Check for compliance with the permissible stresses or proof of fatigue strength<strong>.<\/strong><\/li>\n<\/ul>\n<p>This requires an iterative approach.<\/p>\n<p>The <strong>strength verification<\/strong> is based on the decision whether the spring is subjected to static, quasi-static or dynamic loading. The following criteria should be used for delimitation:<\/p>\n<ul>\n<li><strong><a href=\"https:\/\/blog.federnshop.com\/beanspruchung-druckfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">Static or quasi-static loading:<\/a><\/strong> Static or quasi-static load constant over time (at rest) or load varying over time with less than 10000 strokes in total.<\/li>\n<li><strong><a href=\"https:\/\/blog.federnshop.com\/beanspruchung-druckfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">Dynamic stress<\/a><\/strong>: time-varying loads with more than 10000 strokes. The spring is usually preloaded and subjected to periodic swell loading with a sinusoidal curve, which occurs randomly (stochastically), e.g. in motor vehicle suspensions. In some cases, abrupt changes in force occur.<\/li>\n<\/ul>\n<p>When dimensioning the spring, stress limits must be specified which are based on the <a href=\"https:\/\/blog.federnshop.com\/zugfestigkeit-federwerkstoffe\/\" target=\"_blank\" rel=\"noopener noreferrer\">strength values of the materials<\/a> and take into account the type of stress. For this purpose, a safety factor is included to determine the permissible voltage. After a comparison with the actual existing stress, the spring dimensioning must be revised by an iterative procedure. The following applies: <strong>Nominal voltage \u2264 permissible voltage<\/strong><\/p>\n<h2><\/h2>\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:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Calculation_compression_springs\" >Calculation compression springs<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#General\" >General<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Calculation_formulas_cylindrical_compression_spring\" >Calculation formulas cylindrical compression spring<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Functional_verification_of_compression_springs\" >Functional verification of compression springs<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Strength_verification_compression_spring\" >Strength verification compression spring<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Geometrical_relationships_for_compression_springs\" >Geometrical relationships for compression springs<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Tension_spring_calculation\" >Tension spring calculation<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#General-2\" >General<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Calculation_formulas_cylindrical_tension_spring\" >Calculation formulas cylindrical tension spring<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Functional_proof_of_tension_spring\" >Functional proof of tension spring<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Strength_verification_of_tension_springs\" >Strength verification of tension springs<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Geometrical_relationships_for_tension_springs\" >Geometrical relationships for tension springs<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Calculation_of_torsion_springs_torsion_springs\" >Calculation of torsion springs (torsion springs)<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#General-3\" >General<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Calculation_formulas_cylindrical_torsion_springs_torsion_springs\" >Calculation formulas cylindrical torsion springs (torsion springs)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Functional_verification_of_torsion_springs_torsion_springs\" >Functional verification of torsion springs (torsion springs)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Strength_verification_of_torsion_springs_torsion_springs\" >Strength verification of torsion springs (torsion springs)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/blog.federnshop.com\/en\/design-of-metal-springs-part-2-calculation\/#Geometric_relationships_for_torsion_springs_torsion_springs\" >Geometric relationships for torsion springs (torsion springs)<\/a><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Calculation_compression_springs\"><\/span>Calculation compression springs<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h4><span class=\"ez-toc-section\" id=\"General\"><\/span>General<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>Cold-formed <a href=\"https:\/\/blog.federnshop.com\/federrate-berechnen\/\" target=\"_blank\" rel=\"noopener noreferrer\">cylindrical compression springs<\/a> with constant pitch are most commonly used in practice. The wire is cold formed by winding around a mandrel. Depending on the feed of the rising pin, the coil spacing and the contact of the spring are regulated. After coiling, the spring is tempered in order to reduce residual stresses in the spring and to increase the shear elasticity limit. The <a href=\"https:\/\/blog.federnshop.com\/setzbetrag-druckfedern-2\/\" target=\"_blank\" rel=\"noopener noreferrer\">set amount<\/a> is therefore reduced. Tempering temperatures and times depend on the material; cooling takes place in air at normal room temperature.<\/p>\n<p>Other important operations in spring production are grinding and setting. The spring ends are usually ground from a wire thickness of 0.5 mm to ensure plane-parallel bearing of the spring and optimum force transmission.<\/p>\n<p>If the <a href=\"https:\/\/blog.federnshop.com\/schubspannung-berechnen\/\" target=\"_blank\" rel=\"noopener noreferrer\">shear stress<\/a> exceeds the permissible value when the spring is loaded, a permanent deformation occurs, which is expressed in the reduction of the unstressed length. This process is called &#8220;setting&#8221; in spring technology, which is associated with the terms &#8220;creeping&#8221; and &#8220;<a href=\"https:\/\/blog.federnshop.com\/relaxation-federn\/\" target=\"_blank\" rel=\"noopener noreferrer\"> relaxation<\/a> \u201cFrom materials engineering is to be equated. To counteract this, the compression springs are wound longer by the expected setting amount and later compressed to block length. This setting enables a better material utilization and allows a higher load in later use.<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Calculation_formulas_cylindrical_compression_spring\"><\/span><a href=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Gutekunst_Druckfedern_Formeln_2015.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Calculation formulas cylindrical compression spring<\/a><span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>The calculation of the <a href=\"https:\/\/blog.federnshop.com\/druckfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">compression spring<\/a> is based on the calculation equations from DIN EN 13906-1:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-2846 size-large\" src=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/\/Druckfeder_technisch-1024x719.jpg\" alt=\"Pressure spring technical illustration\" width=\"750\" height=\"527\" data-wp-pid=\"2846\" srcset=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfeder_technisch-1024x719.jpg 1024w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfeder_technisch-300x211.jpg 300w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfeder_technisch-768x539.jpg 768w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfeder_technisch-600x421.jpg 600w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfeder_technisch-150x105.jpg 150w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfeder_technisch-400x281.jpg 400w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfeder_technisch-200x140.jpg 200w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfeder_technisch.jpg 1211w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>Figure: Theoretical compression spring diagram<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Functional_verification_of_compression_springs\"><\/span>Functional verification of compression springs<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>The following applies to cylindrical compression springs made of wire with a circular cross-section:<\/p>\n<p><strong>Formula spring rate:<\/strong> <span class=\"katex-eq\" data-katex-display=\"false\">\\Large R=\\frac{ Gd^{4}}{8D^{3}n}<\/span><\/p>\n<p>follows from R=F\/s:<\/p>\n<p><strong>Spring force : <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large F=\\frac{ Gd^{4}s}{8D^{3}n}<\/span><strong><br \/>\n<\/strong><\/p>\n<p>as well as:<\/p>\n<p><strong>Suspension travel : <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large s=\\frac{8D^{3}nF}{Gd^{4}}<\/span><strong><br \/>\n<\/strong><\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Strength_verification_compression_spring\"><\/span>Strength verification compression spring<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>After the spring dimensions have been determined, the strength must be verified. For this purpose, the existing shear stress is determined:<\/p>\n<p><strong>Tension from force: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\tau=\\frac{8DF}{\\pi d^{3}}<\/span><strong><br \/>\n<\/strong><\/p>\n<p><strong>Voltage from path: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\tau=\\frac{Gds}{\\pi n D^{2}}<\/span><strong><br \/>\n<\/strong><\/p>\n<p>While the shear stress <span class=\"katex-eq\" data-katex-display=\"false\">\\tau<\/span> is to be used for the design of statically or quasi-statically loaded springs, the <a href=\"https:\/\/blog.federnshop.com\/schubspannung-berechnen\/\" target=\"_blank\" rel=\"noopener noreferrer\">corrected shear stress<\/a> <span class=\"katex-eq\" data-katex-display=\"false\">\\tau<\/span><sub>k<\/sub> applies to dynamically loaded springs. The distribution of shear stress in the wire cross-section of a spring is uneven, the highest stress occurs on the inside diameter of the spring. With the tension correction factor k, which depends on the winding ratio (ratio of mean diameter to wire thickness) of the spring, the highest tension can be approximately determined. For <a href=\"https:\/\/blog.federnshop.com\/beanspruchung-druckfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">dynamically loaded compression springs<\/a>, the result is thus:<\/p>\n<p><strong>Corrected shear stress: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\tau_{k}=k\\tau<\/span><strong><br \/>\n<\/strong><\/p>\n<p>where holds for k (according to Bergstr\u00e4sser):<\/p>\n<span class=\"katex-eq\" data-katex-display=\"false\">\\Large k=\\frac{\\frac{D}{d}+0.5}{\\frac{D}{d}-0.75}<\/span>\n<p>Now the comparison is made with the permissible voltage. This is defined as follows:<\/p>\n<p><strong>Allowable voltage: <\/strong><\/p>\n<span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\tau_{{zul}}=0.5\\cdot R_{{m}}<\/span>\n<p>und<\/p>\n<span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\tau_{{czul}}=0.56\\cdot R_{{m}}<\/span>\n<p>The values for the <a href=\"https:\/\/blog.federnshop.com\/zugfestigkeit-federwerkstoffe\/\" target=\"_blank\" rel=\"noopener noreferrer\">Minimum tensile strength R<sub>m<\/sub><\/a> are dependent on the wire thickness and can be found in the standards of the corresponding materials.<\/p>\n<p>As a rule, it must be possible to compress compression springs up to the block length, which is why the permissible stress for the block length is <span class=\"katex-eq\" data-katex-display=\"false\">\\tau<\/span><sub>czul<\/sub> to consider.<\/p>\n<p>At dynamic stress must <a href=\"https:\/\/blog.federnshop.com\/beanspruchung-druckfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">lower and upper voltage (<span class=\"katex-eq\" data-katex-display=\"false\">\\tau<\/span><sub>k1<\/sub> and <span class=\"katex-eq\" data-katex-display=\"false\">\\tau<\/span><sub>k2<\/sub>)<\/a> of the corresponding stroke can be determined. The difference is the stroke voltage. Both the upper tension and the stroke tension must not exceed the corresponding permissible values. These can be taken from the fatigue strength diagrams in EN 13906-1:2002. If the tensions stand up to this comparison, the spring is fatigue-resistant with a maximum number of load cycles of 10<sup>7<\/sup> .<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Geometrical_relationships_for_compression_springs\"><\/span>Geometrical relationships for compression springs<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<table width=\"662\">\n<tbody>\n<tr>\n<td width=\"378\">Spring parameter<\/td>\n<td width=\"284\">Calculation equation<\/td>\n<\/tr>\n<tr>\n<td width=\"378\">Total number of turns<\/td>\n<td width=\"284\">n<sub>t<\/sub> = n + 2<\/td>\n<\/tr>\n<tr>\n<td width=\"378\">Block length of the ground spring<\/td>\n<td width=\"284\">L<sub>c<\/sub> = n<sub>t<\/sub> d<sub>max<\/sub><\/td>\n<\/tr>\n<tr>\n<td width=\"378\">Block length of the unground spring<\/td>\n<td width=\"284\">L<sub>c<\/sub> = (n<sub>t<\/sub> + 1,5)d<sub>max<\/sub><\/td>\n<\/tr>\n<tr>\n<td width=\"378\">Smallest usable length<\/td>\n<td width=\"284\">L<sub>n<\/sub> = L<sub>c<\/sub> +S<sub>a<\/sub><\/td>\n<\/tr>\n<tr>\n<td width=\"378\">Unstressed length<\/td>\n<td width=\"284\">L<sub>0<\/sub> = L<sub>n<\/sub> +s<sub>n<\/sub><\/td>\n<\/tr>\n<tr>\n<td width=\"378\">Sum of the minimum distances between the windings<\/td>\n<td width=\"284\"><span class=\"katex-eq\" data-katex-display=\"false\">\\Large S_{a}=\\left (0.0015 \\frac{D^{2}}{d} + 0.1d \\right )\\cdot n<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"378\">Increase of the outer diameter under load<\/p>\n<p>&nbsp;<\/p>\n<p>pitch<\/td>\n<td width=\"284\"><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\triangle D_{e}=0.1\\frac{S^{2}-08Sd-0.2d^{2}}{D}<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span class=\"katex-eq\" data-katex-display=\"false\">\\Large S=\\frac{L0-d}{n}<\/span> (ground)<\/p>\n<p><span class=\"katex-eq\" data-katex-display=\"false\">\\Large S=\\frac{L0-2.5d}{n}<\/span> (unpolished)<\/p>\n<p>&nbsp;<\/td>\n<\/tr>\n<tr>\n<td width=\"378\">&nbsp;<\/p>\n<p>Buckling spring deflection (valid for different <a href=\"https:\/\/blog.federnshop.com\/federendlagerungen-knickgrenzen\/\" target=\"_blank\" rel=\"noopener noreferrer\">bearing coefficients<\/a> n, see EN 13906-1:2002)<\/td>\n<td width=\"284\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2850\" src=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfedern_Knickfederweg_Formel.png\" alt=\"Compression spring Formula Buckling spring deflection\" width=\"274\" height=\"85\" data-wp-pid=\"2850\" srcset=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfedern_Knickfederweg_Formel.png 274w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfedern_Knickfederweg_Formel-270x85.png 270w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfedern_Knickfederweg_Formel-150x47.png 150w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Druckfedern_Knickfederweg_Formel-200x62.png 200w\" sizes=\"auto, (max-width: 274px) 100vw, 274px\" \/><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>All dynamically stressed springs with a wire thickness &gt; 1 mm should be <a href=\"https:\/\/blog.federnshop.com\/kugelstrahlen-metallfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">shot peened<\/a>. This allows an increase in the continuous stroke strength to be achieved. After both the functional verification and the strength verification have been carried out, various geometry calculations must be carried out and taken into account in order to be able to fit the <a href=\"https:\/\/blog.federnshop.com\/federauswahl\/\" target=\"_blank\" rel=\"noopener noreferrer\">spring<\/a> into the construction of the component. The block length <em>cannot be<\/em> fallen short of because the windings are tightly connected, the smallest usable length <em>should<\/em> not be fallen short of because then a <a href=\"https:\/\/blog.federnshop.com\/federkennlinie\/\" target=\"_blank\" rel=\"noopener noreferrer\">linear force curve<\/a> as well as dynamic load capacity are no longer guaranteed. In addition, the permissible tolerances according to DIN 2095 must be taken into account.<\/p>\n<p>&nbsp;<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Tension_spring_calculation\"><\/span>Tension spring calculation<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h4><span class=\"ez-toc-section\" id=\"General-2\"><\/span>General<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>Extension<a href=\"https:\/\/blog.federnshop.com\/zugfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">springs<\/a> are wound around a mandrel in exactly the same way as compression springs, but with no coil spacing and with different <a href=\"https:\/\/blog.federnshop.com\/oesenformen-zugfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">eyelet shapes\/spring<\/a> ends to attach the spring. The windings are pressed tightly together in the production process. This internal <a href=\"https:\/\/blog.federnshop.com\/zugfedern-wissen\/\" target=\"_blank\" rel=\"noopener noreferrer\">preload F0<\/a> depends on the winding ratio and cannot be finished to an arbitrarily high level. The <a href=\"https:\/\/blog.federnshop.com\/neues-federnberechnungsprogramm\/\" target=\"_blank\" rel=\"noopener noreferrer\">calculation software WinFSB<\/a> from <a href=\"https:\/\/blog.federnshop.com\/gutekunst-federn\/\" target=\"_blank\" rel=\"noopener noreferrer\">Gutekunst Federn<\/a> provides reference values for the amount of preload after entering the respective spring data.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-2852 size-full\" src=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Oesenformen-1.jpg\" alt=\"Tension Springs Oesenformen | Gutekunst Federn\" width=\"998\" height=\"353\" data-wp-pid=\"2852\" srcset=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Oesenformen-1.jpg 998w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Oesenformen-1-300x106.jpg 300w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Oesenformen-1-768x272.jpg 768w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Oesenformen-1-600x212.jpg 600w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Oesenformen-1-150x53.jpg 150w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Oesenformen-1-400x141.jpg 400w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Oesenformen-1-200x71.jpg 200w\" sizes=\"auto, (max-width: 998px) 100vw, 998px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>Image: Common eyelet shapes: a.) half German eyelet; b.) whole German eyelet; c.) Hook eye; d.) English eyelet; e.) rolled hook; f.) Screw-in piece<\/p>\n<p>The advantage of extension springs is that they do <a href=\"https:\/\/blog.federnshop.com\/federendlagerungen-knickgrenzen\/\" target=\"_blank\" rel=\"noopener noreferrer\">not buckle<\/a>; the disadvantage is the larger installation space and the complete interruption of the force flow in the event of spring breakage.<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Calculation_formulas_cylindrical_tension_spring\"><\/span><a href=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Gutekunst_Zugfedern_Formeln_2015.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Calculation formulas cylindrical tension spring<\/a><span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>Corresponding to the calculation equations for compression springs, but taking into account the prestressing force, the following relationships apply to cylindrical tension springs made of round wire (see also Figure 1.8):<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-2853 size-full\" src=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Zugfeder_technisch.jpg\" alt=\"Theoretical tension spring diagram | Gutekunst Federn\" width=\"1003\" height=\"472\" data-wp-pid=\"2853\" srcset=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Zugfeder_technisch.jpg 1003w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Zugfeder_technisch-300x141.jpg 300w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Zugfeder_technisch-768x361.jpg 768w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Zugfeder_technisch-600x282.jpg 600w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Zugfeder_technisch-150x71.jpg 150w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Zugfeder_technisch-400x188.jpg 400w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Zugfeder_technisch-200x94.jpg 200w\" sizes=\"auto, (max-width: 1003px) 100vw, 1003px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>Figure: Theoretical tension spring diagram<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Functional_proof_of_tension_spring\"><\/span>Functional proof of tension spring<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>The following applies to cylindrical tension springs made of wire with a circular cross-section:<\/p>\n<p><strong>Spring rate: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large R=\\frac{Gd^4}{8D^3n}=\\frac{F-F0}{s}<\/span><strong><br \/>\n<\/strong><\/p>\n<p>follows from R=F\/s:<\/p>\n<p><strong>Spring force: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large F=\\frac{Gd^4s}{8D^3n}+F0<\/span><strong><br \/>\n<\/strong><\/p>\n<p>as well as:<\/p>\n<p><strong>Spring travel: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large s=\\frac{8D^3n(F-F0)}{Gd^4}<\/span><strong><br \/>\n<\/strong><\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Strength_verification_of_tension_springs\"><\/span>Strength verification of tension springs<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>As with compression spring calculations, the existing shear stress must be determined.<\/p>\n<p><strong>Shear stress: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\tau=\\frac{8DF}{\\pi d^3}<\/span><strong><br \/>\n<\/strong><\/p>\n<p>Likewise, the corrected stroke stress must be calculated for dynamic loading.<\/p>\n<p><strong>Corrected shear stress: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\tau_{{k}}=k\\tau<\/span><strong><br \/>\n<\/strong><\/p>\n<p><strong>Permissible voltage: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\tau_{{zul}}=0.45 \\cdot R_{{m}}<\/span><\/p>\n<p>The existing maximum voltage \\tau<sub>n<\/sub> for the largest travel s<sub>n<\/sub> is set equal to the permissible voltage. However, in order to avoid <a href=\"https:\/\/blog.federnshop.com\/relaxation-federn\/\" target=\"_blank\" rel=\"noopener noreferrer\">relaxation<\/a>, only 80% of this spring travel should be used in practice.<\/p>\n<span class=\"katex-eq\" data-katex-display=\"false\">\\Large s_{{2}}=0.8 \\cdot s_{{n}}<\/span>\n<p>No generally valid <a href=\"https:\/\/blog.federnshop.com\/dauerfestigkeit\/\" target=\"_blank\" rel=\"noopener noreferrer\">fatigue strength values<\/a> can be given for dynamic stresses, as additional stresses may occur at the <a href=\"https:\/\/blog.federnshop.com\/zugfedern-wissen\/\" target=\"_blank\" rel=\"noopener noreferrer\">bending points of the eyelets<\/a>, some of which may exceed the permissible stresses. Tension springs should therefore only be subjected to static loads if possible. If dynamic stress cannot be avoided, one should go for <a href=\"https:\/\/blog.federnshop.com\/oesenformen-zugfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">angled Eyelets do without and use rolled or screwed-in end pieces<\/a>. A life test under later operating conditions makes sense. A Surface hardening by <a href=\"https:\/\/blog.federnshop.com\/kugelstrahlen-metallfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">shot peening<\/a> is not feasible because of the tight turns.<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Geometrical_relationships_for_tension_springs\"><\/span>Geometrical relationships for tension springs<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<table width=\"662\">\n<tbody>\n<tr>\n<td width=\"265\">Spring parameter<\/td>\n<td width=\"397\">Calculation equation<\/td>\n<\/tr>\n<tr>\n<td width=\"265\">Body length<\/td>\n<td width=\"397\">L<sub>K<\/sub> = (n<sub>t<\/sub>+ 1)d<\/td>\n<\/tr>\n<tr>\n<td width=\"265\">Unstressed length<\/td>\n<td width=\"397\">L<sub>0<\/sub> = L<sub>K<\/sub> + 2 L<sub>H<\/sub><\/td>\n<\/tr>\n<tr>\n<td width=\"265\">Eyelet height half German eyelet<\/td>\n<td width=\"397\">L<sub>H<\/sub> = 0.55D<sub>i<\/sub> to 0.80D<sub>i<\/sub><\/td>\n<\/tr>\n<tr>\n<td width=\"265\">Eyelet height whole German eyelet<\/td>\n<td width=\"397\">L<sub>H<\/sub> = 0.80D<sub>i<\/sub> to 1.10D<sub>i<\/sub><\/td>\n<\/tr>\n<tr>\n<td width=\"265\">Eye height hook eye<\/td>\n<td width=\"397\">L<sub>H<\/sub> &gt; 1.10D<sub>i<\/sub><\/td>\n<\/tr>\n<tr>\n<td width=\"265\">Eyelet height English eyelet<\/td>\n<td width=\"397\">L<sub>H<\/sub> = 1.10D<sub>i<\/sub><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The permissible manufacturing tolerances according to DIN 2097 must be taken into account.<\/p>\n<p>&nbsp;<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Calculation_of_torsion_springs_torsion_springs\"><\/span>Calculation of torsion springs (torsion springs)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h4><span class=\"ez-toc-section\" id=\"General-3\"><\/span>General<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>Coiled cylindrical <a href=\"https:\/\/blog.federnshop.com\/schenkelfedern-torsionsfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">torsion springs<\/a> have essentially the same shape as cylindrical <a href=\"https:\/\/blog.federnshop.com\/druckfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">compression springs<\/a> and <a href=\"https:\/\/blog.federnshop.com\/zugfedern\/\" target=\"_blank\" rel=\"noopener noreferrer\">extension springs<\/a>, but with the exception of the spring ends. These are bent in a leg shape to allow the spring body to rotate around the spring axis. This means that they can be used in a wide range of applications, e.g. as return springs or hinge springs. The torsion spring should be mounted on a guide mandrel and the load should only be applied in the winding direction. The inner diameter is reduced in this case. The springs are usually coiled without pitch. However, if friction is absolutely undesirable, torsion springs can also be manufactured with coil spacing. In the case of dynamic loading, care must be taken to ensure that there are no sharp-edged bends at the ends of the springs in order to avoid unpredictable stress peaks.<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Calculation_formulas_cylindrical_torsion_springs_torsion_springs\"><\/span><a href=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Gutekunst_Schenkelfedern_Formeln_2015.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Calculation formulas cylindrical torsion springs<\/a> (torsion springs)<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>The calculation is carried out according to the guidelines of EN 13906-3:2001:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2855\" src=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch.jpg\" alt=\"Theoretical torsion spring diagram | Gutekunst Federn\" width=\"1053\" height=\"843\" data-wp-pid=\"2855\" srcset=\"https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch.jpg 1053w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch-300x240.jpg 300w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch-768x615.jpg 768w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch-1024x820.jpg 1024w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch-600x480.jpg 600w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch-150x120.jpg 150w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch-400x320.jpg 400w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch-200x160.jpg 200w, https:\/\/blog.federnshop.com\/wp-content\/uploads\/Schenkelfeder_technisch-800x640.jpg 800w\" sizes=\"auto, (max-width: 1053px) 100vw, 1053px\" \/><\/p>\n<p>Figure: Theoretical torsion spring \/ torsion spring diagram<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Functional_verification_of_torsion_springs_torsion_springs\"><\/span>Functional verification of torsion springs (torsion springs)<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p><strong>Fed Mom Rate: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large R_{M}=\\frac{M}{\\alpha}=\\frac{d^4E}{3667Dn}<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Spring moment: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large M=FR_{H}=\\frac{d^4E\\alpha}{3667Dn}<\/span><strong><br \/>\n<\/strong><\/p>\n<p>&nbsp;<\/p>\n<p><strong>Angle of rotation: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\alpha=\\frac{3667DMn}{Ed^4}<\/span><strong><br \/>\n<\/strong><\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Strength_verification_of_torsion_springs_torsion_springs\"><\/span>Strength verification of torsion springs (torsion springs)<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>The existing bending stress is determined and compared with the permissible stress. In the case of dynamic loading, the corrected stress must again be used for comparison.<\/p>\n<p><strong>Bending stress: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\sigma=\\frac{32M}{\\pi d^3}<\/span><\/p>\n<p><strong>Corrected bending stress: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\sigma_{{q}}=q \\sigma<\/span><strong><br \/>\n<\/strong><\/p>\n<p>where q is:<\/p>\n<span class=\"katex-eq\" data-katex-display=\"false\">\\Large q=\\frac{\\frac{D}{d}+0.07}{\\frac{D}{d}-0.75}<\/span>\n<p>&nbsp;<\/p>\n<p><strong>Permissible bending stress: <\/strong><span class=\"katex-eq\" data-katex-display=\"false\">\\Large \\sigma_{{zul}}=0.7Rm<\/span><strong><br \/>\n<\/strong><\/p>\n<p>At dynamic stress must lower and upper voltage (t<sub>k<\/sub>1 and t<sub>k<\/sub>2) of the corresponding stroke can be determined. The difference is the stroke voltage. Both the upper tension and the stroke tension must not exceed the corresponding permissible values. For spring steel wire, these can be taken from the fatigue strength diagrams in EN 13906-3:2001. If the tensions stand up to this comparison, the spring is fatigue-resistant with a maximum number of load cycles of 10<sup> 7<\/sup> .<\/p>\n<p>&nbsp;<\/p>\n<h4><span class=\"ez-toc-section\" id=\"Geometric_relationships_for_torsion_springs_torsion_springs\"><\/span>Geometric relationships for torsion springs (torsion springs)<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<table>\n<tbody>\n<tr>\n<td width=\"416\">Spring parameter<\/td>\n<td width=\"246\">Calculation equation<\/td>\n<\/tr>\n<tr>\n<td width=\"416\">Reduction of the inner diameter at maximum load<\/td>\n<td width=\"246\"><span class=\"katex-eq\" data-katex-display=\"false\">\\Large Di_{n}=\\frac{Dn}{n+\\frac{\\alpha}{360}}-d<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"416\">Unloaded body length<\/td>\n<td width=\"246\"><span class=\"katex-eq\" data-katex-display=\"false\">\\Large Lk=(n+1.5)d<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"416\">Body length in maximum loaded condition<\/td>\n<td width=\"246\"><span class=\"katex-eq\" data-katex-display=\"false\">\\Large Lk_{n}=(n+1.5+\\frac{\\alpha}{360})d<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"416\">Spring travel<\/td>\n<td width=\"246\"><span class=\"katex-eq\" data-katex-display=\"false\">\\Large s_{n}= \\frac{\\alpha_{n}R_{H}}{57.3}<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>In addition, the manufacturing tolerances according to DIN 2194 must be taken into account.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>A summary of the article &#8220;Design of a metal spring&#8221;, consisting of <a href=\"https:\/\/blog.federnshop.com\/auslegung-metallfedern-grundlagen\/\" target=\"_blank\" rel=\"noopener noreferrer\">part 1 &#8220;Basics&#8221;<\/a> and part 2 &#8220;Calculation&#8221;, is also available for download in the <a href=\"https:\/\/www.federnshop.com\/download\/pdf\/Gutekunst-Federn-1x1-2013-E.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">Gutekunst Federn 1&#215;1<\/a>.<\/strong><\/p>\n<p>If you require an <a href=\"https:\/\/blog.federnshop.com\/massdaten-federauslegung\/\" target=\"_blank\" rel=\"noopener noreferrer\">individual spring design<\/a>, simply email us the key data of the required metal spring to <a href=\"mailto:service@federnshop.com\">service@gutekunst-co.com<\/a>, contact our technical department by telephone on (+49) 035877 227-11 or use the <a href=\"https:\/\/blog.federnshop.com\/neues-federnberechnungsprogramm\/\" target=\"_blank\" rel=\"noopener noreferrer\">Gutekunst spring calculation program WinFSB<\/a> at <a href=\"https:\/\/www.federnshop.com\">https:\/\/www.federnshop.com<\/a> for free calculation of compression springs, extension springs and torsion springs.<\/p>\n<p>&nbsp;<\/p>\n<p><em>For more information:<\/em><\/p>\n<ul>\n<li><a href=\"https:\/\/blog.federnshop.com\/druckfedern-auslegung-video\/\" target=\"_blank\" rel=\"noopener noreferrer\">Compression spring design (video)<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/blog.federnshop.com\/zugfedern-auslegung-video\/\" target=\"_blank\" rel=\"noopener noreferrer\">Extension springs design (video)<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/blog.federnshop.com\/auslegung-metallfedern-grundlagen\/\" target=\"_blank\" rel=\"noopener noreferrer\">Design of metal springs &#8211; Part 1 &#8220;Fundamentals<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/blog.federnshop.com\/massdaten-federauslegung\/\" target=\"_blank\" rel=\"noopener noreferrer\">Dimension data for spring design<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/blog.federnshop.com\/neues-federnberechnungsprogramm\/\">Spring calculation program WinFSB 8<\/a><\/li>\n<\/ul>\n<ul>\n<li><a href=\"https:\/\/blog.federnshop.com\/federstahldraht\/\" target=\"_blank\" rel=\"noopener noreferrer\">Spring steel wires and their properties<\/a><\/li>\n<\/ul>\n<p>&nbsp;<\/p>","protected":false},"excerpt":{"rendered":"<p>In the first part of this two-part series Gutekunst Federn informed about the basics of spring design. In this second part you will find the concrete calculation data for the design of compression springs, extension springs and torsion springs (torsion<\/p>\n","protected":false},"author":4,"featured_media":6726,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"footnotes":""},"categories":[858,860,550,457,458,863,857],"tags":[1515,1498,1518,616,437,438],"class_list":["post-6713","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-compression-springs","category-extension-springs","category-industry-en","category-knowledge","category-press-release","category-special-springs","category-wire-springs","tag-berechnungsformeln-en","tag-federberechnung-en","tag-formeln-en","tag-schenkelfedern-en","tag-springs","tag-tension-springs"],"_links":{"self":[{"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/posts\/6713","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/comments?post=6713"}],"version-history":[{"count":13,"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/posts\/6713\/revisions"}],"predecessor-version":[{"id":11201,"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/posts\/6713\/revisions\/11201"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/media\/6726"}],"wp:attachment":[{"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/media?parent=6713"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/categories?post=6713"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.federnshop.com\/en\/wp-json\/wp\/v2\/tags?post=6713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}