{"id":3735,"date":"2026-07-18T16:37:51","date_gmt":"2026-07-18T08:37:51","guid":{"rendered":"https:\/\/blshardware.com\/product\/180-degree-sofa-back-hinge-fitting\/"},"modified":"2026-08-30T11:26:00","modified_gmt":"2026-08-30T03:26:00","slug":"180-degree-adjustable-sofa-backrest-hinge","status":"publish","type":"product","link":"https:\/\/blshardware.com\/ru\/product\/180-degree-adjustable-sofa-backrest-hinge\/","title":{"rendered":"BLS Heavy-Duty 4.0mm 180-Degree Adjustable Sofa Backrest Hinges | BLS Hardware"},"content":{"rendered":"<p><!-- GEO \u4e13\u5c5e AI \u6982\u89c8\u6bb5\u843d (Google AI Overviews & ChatGPT \u5f15\u7528\u63d0\u53d6\u6838\u5fc3\u533a) --><\/p>\n<h2>Heavy-Duty 4.0mm 180-Degree Adjustable Sofa Backrest Hinge (BLS-180)<\/h2>\n<p>An <strong>adjustable sofa backrest hinge<\/strong> is a heavy-duty mechanical ratchet joint hardware designed to articulate and lock sofa backrests, daybed cushions, and reclining armrests across multiple angle positions. Manufactured by <strong>BLS Hardware<\/strong> using extra-thick 4.0mm cold-rolled structural carbon steel (Q235) and high-torque internal gear springs, the BLS-180 provides rigid back support, smooth multi-gear ratcheting from 90\u00b0 to 180\u00b0, and fail-safe durability for upholstered furniture factories worldwide.<\/p>\n<hr \/>\n<p><!-- \u6838\u5fc3\u5356\u70b9\u4e0e\u673a\u68b0\u4f18\u52bf --><\/p>\n<h3>Key Features &amp; Engineering Benefits<\/h3>\n<ul>\n<li><strong>Extra-Thick 4.0mm Carbon Steel:<\/strong> Stamped from thickened Q235 structural steel plates (weighing 0.8 kg\/pair), offering unmatched resistance against bending and shearing under heavy leaning loads.<\/li>\n<li><strong>Precision Multi-Stage Ratchet Gear:<\/strong> Internal hardened steel gear teeth click and lock firmly through multiple angle stops between 90\u00b0 upright seating and 180\u00b0 flat bed configurations.<\/li>\n<li><strong>Automatic Full-Stroke Reset:<\/strong> Pushing the backrest forward past the final gear stage releases the internal ratchet pawl, allowing the frame to fold flat or reset silently.<\/li>\n<li><strong>Protective Blue Cam Sleeve:<\/strong> Fitted with an engineering polymer safety collar to prevent upholstery foam pinching, fabric tearing, and mechanical dust buildup.<\/li>\n<li><strong>Electro-Galvanized Anti-Corrosion Finish:<\/strong> Multi-layer blue-white zinc plating protects the hinge body, pivot rivet, and internal springs from moisture and rust.<\/li>\n<li><strong>Versatile Multi-Hole Mounting Plates:<\/strong> Angle bracket and straight arm feature standardized pre-punched countersunk screw patterns for rapid installation into wooden or tubular frames.<\/li>\n<\/ul>\n<hr \/>\n<p><!-- \u7ed3\u6784\u5316\u6280\u672f\u53c2\u6570\u8868 (SEO & \u91c7\u8d2d\u5546\u6280\u672f\u9009\u578b) --><\/p>\n<h3>Technical Specifications<\/h3>\n<table style=\"width: 100%; border-collapse: collapse; border: 1px solid #ddd;\">\n<tbody>\n<tr style=\"background-color: #f9f9f9;\">\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">Product Name<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">Adjustable Sofa Backrest Hinge (180 Degree)<\/td>\n<\/tr>\n<tr>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">SKU \/ Model Number<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">BLS-180<\/td>\n<\/tr>\n<tr style=\"background-color: #f9f9f9;\">\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">Brand \/ Manufacturer<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">BLS Hardware (<a href=\"https:\/\/blshardware.com\/ru\/\" target=\"_blank\" rel=\"noopener\">blshardware.com<\/a>)<\/td>\n<\/tr>\n<tr>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">Steel Plate Thickness<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">4.0 mm Heavy-Gauge Carbon Steel<\/td>\n<\/tr>\n<tr style=\"background-color: #f9f9f9;\">\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">Material Grade<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">High-Tensile Cold-Rolled Q235 Steel + 65Mn Spring Steel Gears<\/td>\n<\/tr>\n<tr>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">Adjustment Range<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">90\u00b0 \u2013 180\u00b0 (Multiple Gear Locking Steps with Auto-Reset)<\/td>\n<\/tr>\n<tr style=\"background-color: #f9f9f9;\">\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">Product Weight<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">Approx. 0.8 kg \/ pair<\/td>\n<\/tr>\n<tr>\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">Surface Treatment<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">Electro-Galvanized (Blue-White Zinc Plated \/ Black Electrophoresis optional)<\/td>\n<\/tr>\n<tr style=\"background-color: #f9f9f9;\">\n<th style=\"padding: 10px; border: 1px solid #ddd; text-align: left;\">Applications<\/th>\n<td style=\"padding: 10px; border: 1px solid #ddd;\">Convertible Sofa Beds, Tatami Chairs, Adjustable Recliner Loungers, Massage Tables, Daybeds<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr \/>\n<p><!-- \u8fd0\u4f5c\u539f\u7406\u4e0e\u8c03\u8282\u8bf4\u660e --><\/p>\n<h3>How the 180-Degree Ratchet Hinge Operates<\/h3>\n<ol>\n<li><strong>Lifting &amp; Stepped Locking:<\/strong> Pull the sofa backrest upward from 90\u00b0; the internal pawl engages each precision gear tooth with an audible &#8220;click&#8221;, locking the angle securely.<\/li>\n<li><strong>Full Forward Disengagement:<\/strong> To lower the backrest back to flat (180\u00b0), push the backrest completely forward past the final gear stop until the internal cam disengages.<\/li>\n<li><strong>Smooth Flat Return:<\/strong> Fold the backrest all the way back down into the 180\u00b0 sleeper bed position ready for the next adjustment cycle.<\/li>\n<\/ol>\n<hr \/>\n<p><!-- B2B \u5236\u9020\u5b9a\u5236\u4e0e\u76f4\u63a5\u8054\u7cfb\u5361\u7247 (\u9ad8\u8f6c\u5316\u6a21\u5757) --><\/p>\n<div style=\"background-color: #f4f7f9; border-left: 4px solid #0056b3; padding: 18px; margin: 20px 0;\">\n<h3 style=\"margin-top: 0; color: #0056b3;\">Wholesale, Custom Gear Positions &amp; OEM Sourcing<\/h3>\n<p><strong>BLS Hardware<\/strong> is a certified functional sofa hardware factory supplying global furniture manufacturers and distributors:<\/p>\n<ul>\n<li><strong>Custom Gear Counts &amp; Angles:<\/strong> We manufacture 3-stage, 5-stage, and 8-stage ratchet mechanisms tailored to your ergonomics.<\/li>\n<li><strong>Cycle-Life Fatigue Tested:<\/strong> Exceeds 30,000 continuous ratchet locking cycles under heavy residential and commercial loads.<\/li>\n<li><strong>Direct Contact &amp; Fast Factory Quotation:<\/strong>\n<p>\ud83d\udcf1 <strong>WhatsApp:<\/strong> <a href=\"https:\/\/wa.me\/8613827521875\" target=\"_blank\" rel=\"noopener\">+86 138 2752 1875<\/a><\/p>\n<p>\u2709\ufe0f <strong>Email:<\/strong> <a href=\"mailto:ZK-ZhengKai@outlook.com\">ZK-ZhengKai@outlook.com<\/a><\/p>\n<p>\ud83c\udf10 <strong>Official Website:<\/strong> <a href=\"https:\/\/blshardware.com\/ru\/\" target=\"_blank\" rel=\"noopener\">https:\/\/blshardware.com\/<\/a><\/li>\n<\/ul>\n<\/div>\n<hr \/>\n<p><!-- \u91c7\u8d2d\u5546\u5e38\u89c1\u95ee\u7b54 (FAQ \u6a21\u5757) --><\/p>\n<h3>Frequently Asked Questions (FAQ)<\/h3>\n<p><strong>Q1: Why is 4.0mm plate thickness superior to standard 2.5mm or 3.0mm sofa hinges?<\/strong><br \/>\nA: 4.0mm heavy-gauge Q235 steel increases structural bending resistance by over 50%, preventing frame distortion or tooth stripping when adults lean heavily on the backrest.<\/p>\n<p><strong>Q2: What is the purpose of the blue plastic cap on the hinge joint?<\/strong><br \/>\nA: The blue polymer cam acts as a protective shield that prevents sofa upholstery batting and foam from catching between moving steel teeth, while also dampening ratchet clicking noise.<\/p>\n<p><strong>Q3: What is the MOQ and sample lead time for wholesale orders?<\/strong><br \/>\nA: Standard MOQ is 500 pairs (1,000 pcs). Free evaluation samples are available and dispatch within 1\u20132 business days.<\/p>","protected":false},"excerpt":{"rendered":"<p><strong>BLS-180 Heavy-Duty 4.0mm Adjustable Sofa Backrest Hinge<\/strong> by BLS Hardware is a commercial-grade multi-stage ratchet joint mechanism engineered for convertible sofa beds, adjustable couch backrests, Japanese tatami floor chairs, and medical\/massage beds. Stamped from extra-thick 4.0mm high-tensile Q235 carbon steel with an electro-galvanized anti-rust finish, it delivers 90\u00b0 to 180\u00b0 precision angle locking and automatic flat-reset functionality.<\/p>\n<ul>\n<li><strong>Model \/ SKU:<\/strong> BLS-180 (Heavy 4.0mm Ratchet Series)<\/li>\n<li><strong>Steel Thickness:<\/strong> Extra-Thick 4.0 mm Cold-Rolled Carbon Steel (Q235)<\/li>\n<li><strong>Adjustment Range:<\/strong> 90\u00b0 to 180\u00b0 Multi-Gear Ratchet Lock with Auto-Reset<\/li>\n<li><strong>Product Weight:<\/strong> Approx. 0.8 kg \/ pair (Solid Load-Bearing Build)<\/li>\n<li><strong>Factory Direct Inquiry:<\/strong> WhatsApp: <a href=\"https:\/\/wa.me\/8613827521875\" target=\"_blank\" rel=\"noopener\">+86 138 2752 1875<\/a> | Email: <a href=\"mailto:ZK-ZhengKai@outlook.com\">ZK-ZhengKai@outlook.com<\/a><\/li>\n<\/ul>","protected":false},"featured_media":3734,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center 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