{"id":3076,"date":"2026-10-08T17:17:06","date_gmt":"2026-10-08T17:17:06","guid":{"rendered":"https:\/\/yocl.com\/?wpr2_import=f3cf868671a231d98b66f6eb712a054384fe3fa739e3bd359eb2729d03ed3a2b"},"modified":"2026-10-08T17:17:06","modified_gmt":"2026-10-08T17:17:06","slug":"2-1-vs-3-1-vs-4-1-heat-shrink-tubing","status":"publish","type":"post","link":"https:\/\/yocl.com\/fr\/2-1-vs-3-1-vs-4-1-heat-shrink-tubing\/","title":{"rendered":"2:1 vs 3:1 vs 4:1 Gaines thermor\u00e9tractables : quel taux de r\u00e9treint vous faut-il ?"},"content":{"rendered":"<p><strong>Choisissez le rapport de r\u00e9treint \u00e0 partir de la transition de diam\u00e8tre que le tube doit couvrir.<\/strong> Son al\u00e9sage fourni doit d\u00e9gager la plus grande caract\u00e9ristique, et son al\u00e9sage r\u00e9cup\u00e9r\u00e9 librement doit \u00eatre plus petit que la surface la plus \u00e9troite qu'il doit saisir. Une 2:1 de taille appropri\u00e9e peut d\u00e9j\u00e0 accomplir cette t\u00e2che. Envisagez 3:1 ou 4:1 lorsque les dimensions r\u00e9elles n\u00e9cessitent une plage de r\u00e9cup\u00e9ration plus large.<\/p>\n<p>Un rapport plus \u00e9lev\u00e9 seul ne fournit pas d'adh\u00e9sif, une connexion scell\u00e9e ou une puissance \u00e9lectrique plus \u00e9lev\u00e9e. Comparez d'abord la g\u00e9om\u00e9trie, puis v\u00e9rifiez la construction et l'utilisation exactes du produit.<\/p>\n<h2>Comparez 2:1, 3:1 et 4:1 sur la m\u00eame g\u00e9om\u00e9trie<\/h2>\n<p>Le rapport de r\u00e9treint d\u00e9crit la relation nominale entre <strong>le diam\u00e8tre int\u00e9rieur (ID) expans\u00e9<\/strong> et <strong>l'ID r\u00e9cup\u00e9r\u00e9 librement<\/strong>. Pour une arithm\u00e9tique id\u00e9alis\u00e9e\u00a0:<\/p>\n<p><strong>ID de r\u00e9cup\u00e9ration libre = ID expans\u00e9 \u00f7 nombre de ratio<\/strong><\/p>\n<p>Avec le m\u00eame al\u00e9sage expans\u00e9 hypoth\u00e9tique 15 mm, 2 : 1 donne 7.5 mm, 3 : 1 donne 5 mm, et 4 : 1 donne 3.75 mm. Ce sont des points finaux illustratifs sans objet interne restreignant la r\u00e9cup\u00e9ration, plut\u00f4t que des dimensions garanties de trois produits du catalogue. Le ratio d\u00e9crit la r\u00e9cup\u00e9ration du diam\u00e8tre ; il ne divise pas la longueur coup\u00e9e ni n'identifie le nombre de parois. Le <a href=\"https:\/\/yocl.com\/fr\/what-is-heat-shrink-tubing\/\">guide de terminologie des tubes thermor\u00e9tractables<\/a> explique ces champs distincts.<\/p>\n<figure class=\"wp-block-image\">\n<img decoding=\"async\" src=\"https:\/\/yocl.com\/wp-content\/uploads\/2026\/10\/2-1-vs-3-1-vs-4-1-heat-shrink-tubing-ratio-comparison.webp\" alt=\"Hypothetical 15 mm expanded bore compared with 7.5, 5 and 3.75 mm freely recovered bores for 2:1, 3:1 and 4:1 tubing\"><figcaption>Conceptuel, pas \u00e0 l'\u00e9chelle. Arithm\u00e9tique nominale pour un al\u00e9sage expans\u00e9 partag\u00e9 15 mm. Les al\u00e9sages r\u00e9cup\u00e9r\u00e9s vides illustrent la r\u00e9cup\u00e9ration libre ; les limites r\u00e9elles du produit r\u00e9gissent toujours la s\u00e9lection de la taille.<\/figcaption><\/figure>\n<p>Maintenant, tenez la plus grande caract\u00e9ristique ronde que le tube doit franchir \u00e0 <strong>13 mm diam\u00e8tre ext\u00e9rieur (DE)<\/strong>. Changez uniquement la surface ronde la plus petite o\u00f9 il doit se poser. Les trois manchons hypoth\u00e9tiques commencent avec le m\u00eame al\u00e9sage 15 mm, donc la comparaison isole leur plage de r\u00e9cup\u00e9ration.<\/p>\n<table>\n<thead>\n<tr>\n<th>Plus petit OD d'atterrissage<\/th>\n<th>2:1: ID libre 7.5 mm<\/th>\n<th>3:1: ID libre 5 mm<\/th>\n<th>4:1: ID libre 3.75 mm<\/th>\n<th>Ratio suffisant dans ces hypoth\u00e8ses<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>9 mm<\/td>\n<td>En dessous de l'OD d'atterrissage<\/td>\n<td>En dessous de l'OD d'atterrissage<\/td>\n<td>En dessous de l'OD d'atterrissage<\/td>\n<td>Les trois ; 2:1 suffit d\u00e9j\u00e0 g\u00e9om\u00e9triquement<\/td>\n<\/tr>\n<tr>\n<td>6 mm<\/td>\n<td>Trop grand<\/td>\n<td>En dessous de l'OD d'atterrissage<\/td>\n<td>En dessous de l'OD d'atterrissage<\/td>\n<td>3:1 ou 4:1 ; 3:1 suffit d\u00e9j\u00e0 g\u00e9om\u00e9triquement<\/td>\n<\/tr>\n<tr>\n<td>4.5 mm<\/td>\n<td>Trop grand<\/td>\n<td>Trop grand<\/td>\n<td>En dessous de l'OD d'atterrissage<\/td>\n<td>4:1 seulement<\/td>\n<\/tr>\n<tr>\n<td>3 mm<\/td>\n<td>Trop grand<\/td>\n<td>Trop grand<\/td>\n<td>Trop grand<\/td>\n<td>Aucun de ces trois candidats<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Ceci est un <strong>comparaison hypoth\u00e9tique contr\u00f4l\u00e9e<\/strong>, pas une liste de tailles approuv\u00e9e. La diff\u00e9rence 2 mm entre le trou dilat\u00e9 suppos\u00e9 et le diam\u00e8tre ext\u00e9rieur de passage est un \u00e9cart exemple, pas un d\u00e9gagement recommand\u00e9. Les tol\u00e9rances r\u00e9elles, la marge d'installation et la plage d'application autoris\u00e9e restent \u00e0 v\u00e9rifier.<\/p>\n<p>La derni\u00e8re ligne compte : m\u00eame 4:1 peut \u00eatre insuffisant. Un rapport plus \u00e9lev\u00e9 \u00e9tend la plage nominale, mais aucune \u00e9tiquette ne garantit l'ajustement sur chaque transition. Inversement, la premi\u00e8re ligne ne donne aucune raison dimensionnelle de rejeter 2:1 simplement parce que 4:1 est disponible.<\/p>\n<h2>Transformer un candidat de ratio en une taille de tube exacte<\/h2>\n<p>Pour les pi\u00e8ces rondes et les tubes ouverts, v\u00e9rifiez les deux limites de <strong>une rang\u00e9e de taille exacte<\/strong>:<\/p>\n<ul>\n<li><strong>Minimum supplied ID &gt; largest pass-over OD<\/strong><\/li>\n<li><strong>Maximum freely recovered ID &lt; smallest landing OD<\/strong><\/li>\n<\/ul>\n<p>de la NASA <a href=\"https:\/\/standards.nasa.gov\/sites\/default\/files\/standards\/KSC\/F\/KSC-E-165-REV-F.pdf\" target=\"_blank\" rel=\"noopener\">KSC-E-165 R\u00e9vision F, \u00a73.8.1.1.1(a)<\/a> uses this expanded-larger\/recovered-smaller principle within Kennedy Space Center electrical ground-support-equipment fabrication. It supports the dimensional relationship, without approving a YOCL product or assembly.<\/p>\n<p>Retain the table&#8217;s minimum, maximum and \u00b1 signs, component tolerances and specified application allowance. Equality supplies no assured margin. A model&#8217;s stated application range may further restrict the usable diameters, even where the preliminary inequalities pass.<\/p>\n<p>If you increase the supplied size to clear a connector, recheck the recovered limit of that larger row. Changing the first diameter can also change the second. Use the <a href=\"https:\/\/yocl.com\/fr\/heat-shrink-tubing-size-chart\/\">tableau des tailles de gaines thermor\u00e9tractables<\/a> for the full lookup and limit conventions.<\/p>\n<h3>Free recovery is different from installed fit<\/h3>\n<p>A sleeve installed over a cable stops contracting against the surface inside it. In the hypothetical 4:1 example, a 4.5 mm jacket prevents the bore reaching its empty 3.75 mm endpoint. The endpoint therefore does not specify installed ID, outside diameter or wall thickness.<\/p>\n<figure class=\"wp-block-image\">\n<img decoding=\"async\" src=\"https:\/\/yocl.com\/wp-content\/uploads\/2026\/10\/2-1-vs-3-1-vs-4-1-heat-shrink-tubing-installed-fit.webp\" alt=\"Conceptual comparison of an empty 3.75 mm freely recovered bore and the same nominal 4:1 sleeve constrained by a 4.5 mm cable jacket\"><figcaption>Hypothetical 4:1 example: an internal jacket restricts recovery. Schematic wall thickness is illustrative; the free-recovery bore does not determine installed outside diameter.<\/figcaption><\/figure>\n<p>For a sleeve spanning several surfaces, check the smallest required landing as well as the largest feature it crosses. Irregular connectors, flat busbars, bundles and branches need their actual envelope and contact geometry reviewed; one round OD cannot describe every gap or valley.<\/p>\n<h2>A real YOCL 3:1 vs 4:1 comparison<\/h2>\n<p>Le <a href=\"https:\/\/yocl.com\/fr\/product\/3-1-zero-halogen-single-wall-heat-shrink-tubing\/\">3:1 Zero-Halogen single-wall product<\/a> et <a href=\"https:\/\/yocl.com\/fr\/product\/4-1-zero-halogen-single-wall-heat-shrink-tubing\/\">4:1 Zero-Halogen single-wall product<\/a> offer a useful same-construction comparison. Both declare no internal adhesive. Their 20 mm supplied-bore entries have different recovered limits:<\/p>\n<table>\n<thead>\n<tr>\n<th>Champ publi\u00e9<\/th>\n<th>3:1 single wall<\/th>\n<th>4:1 single wall<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Size entry<\/td>\n<td>20.0\/6.7 mm<\/td>\n<td>20.0\/5.0 mm<\/td>\n<\/tr>\n<tr>\n<td>Minimum supplied ID<\/td>\n<td>20.0 mm<\/td>\n<td>\u226520.0 mm<\/td>\n<\/tr>\n<tr>\n<td>Maximum ID after recovery<\/td>\n<td>6.7 mm<\/td>\n<td>\u22645.0 mm<\/td>\n<\/tr>\n<tr>\n<td>Adh\u00e9sif interne<\/td>\n<td>Aucun<\/td>\n<td>Aucun<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>These are manufacturer declarations from the respective dimension tables, checked 9 October 2026. The 3:1 page establishes minimum and maximum through its column headings; the 4:1 page also prints the inequalities in each row.<\/p>\n<p>For hypothetical <strong>18 mm pass-over and 6 mm landing<\/strong> dimensions, both supplied minima clear the large feature. The 3:1 row&#8217;s 6.7 mm recovered maximum does not establish contraction below 6 mm; the 4:1 row&#8217;s 5.0 mm maximum does. That makes the latter a dimensional candidate, still subject to allowance and application review. It does not prove a sealed joint.<\/p>\n<p>Keep the published 6.7 mm limit. Replacing it with 20 \u00f7 3 would substitute nominal arithmetic for the actual declaration.<\/p>\n<h2>Check construction and duty alongside the ratio<\/h2>\n<p>The unlined 4:1 example shows why ratio cannot identify adhesive. Where a bonded interface is required, select an appropriate lined product and assess compatibility, contact geometry and sealing evidence. Use the <a href=\"https:\/\/yocl.com\/fr\/single-wall-vs-dual-wall-heat-shrink-tubing\/\">comparaison entre paroi simple et paroi double<\/a> for that decision.<\/p>\n<p>Compare actual wall fields and their measurement states rather than assuming 4:1 is thicker or stronger. Also check coverage and declared longitudinal change, permitted recovery conditions, service temperature, electrical duty and required environmental evidence for the exact grade. Diameter ratio supplies none of those values.<\/p>\n<p>A tight exterior or visible adhesive at an end cannot by itself verify the complete sealing interface. If an installed sleeve is already loose, damaged or has an unverified seal, the <a href=\"https:\/\/yocl.com\/fr\/why-heat-shrink-tubing-splits-or-fails-to-seal\/\">heat-shrink failure guide<\/a> addresses that separate investigation.<\/p>\n<h2>Make the final choice from the products that pass<\/h2>\n<p>Keep 2:1 in consideration when its exact size meets both fit checks and the required function. Move to 3:1 or 4:1 when their documented recovery range solves a transition the lower-ratio candidate cannot cover. If several products pass, compare their construction, installed space, process and duty. If none passes, revise the exact size or connection arrangement instead of assuming extra heat will deliver extra recovery.<\/p>\n<p>For a YOCL size review, provide the largest pass-over dimension, smallest landing dimension, required coverage, jacket material and intended duty through the <a href=\"https:\/\/yocl.com\/fr\/heat-shrink-tubing-manufacturer\/#range\">gamme de produits de gaines thermor\u00e9tractables<\/a>. Request the matching size limits, permitted application range and installation information so the final selection identifies a product and size, not just \u201c4:1 heat shrink.\u201d<\/p>\n<h2>R\u00e9f\u00e9rences<\/h2>\n<ul>\n<li>Centre spatial Kennedy de la NASA \u2014 <a href=\"https:\/\/standards.nasa.gov\/sites\/default\/files\/standards\/KSC\/F\/KSC-E-165-REV-F.pdf\" target=\"_blank\" rel=\"noopener\">KSC-E-165 Revision F, 20 December 2021<\/a>, <em>Electrical Ground Support Equipment Fabrication, Specification for<\/em>. \u00a73.8.1.1.1(a), printed page 59; scoped expanded\/recovered size principle.<\/li>\n<li>YOCL Informations produit \u2014 <a href=\"https:\/\/yocl.com\/fr\/product\/3-1-zero-halogen-single-wall-heat-shrink-tubing\/\">3:1 Gaines thermor\u00e9tractables mono-paroi sans halog\u00e8ne<\/a>. 20.0\/6.7 mm row, dimension headings and absence of adhesive; checked 9 October 2026.<\/li>\n<li>YOCL Informations produit \u2014 <a href=\"https:\/\/yocl.com\/fr\/product\/4-1-zero-halogen-single-wall-heat-shrink-tubing\/\">4:1 Gaines thermor\u00e9tractables mono-paroi sans halog\u00e8ne<\/a>. 20.0\/5.0 mm row, supplied\/recovered bounds and absence of adhesive; checked 9 October 2026.<\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>Choose the shrink ratio from the diameter transition the tubing must bridge. Its supplied bore must clear the largest feature, and its freely recovered bore must be smaller than the narrowest surface it needs to grip. A suitable 2:1 size can already complete that job. Consider 3:1 or 4:1 when the actual dimensions require a [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":3075,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[165],"tags":[],"class_list":["post-3076","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-heat-shrink-insulation"],"_links":{"self":[{"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/posts\/3076","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/comments?post=3076"}],"version-history":[{"count":1,"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/posts\/3076\/revisions"}],"predecessor-version":[{"id":3077,"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/posts\/3076\/revisions\/3077"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/media\/3075"}],"wp:attachment":[{"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/media?parent=3076"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/categories?post=3076"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yocl.com\/fr\/wp-json\/wp\/v2\/tags?post=3076"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}