Overview
The American-Style Vertical Sliding Sash Window Hardware Kit (Constant-Force Spring Counterbalance System) is an engineered, architectural-grade sash balance and locking mechanism designed for traditional and contemporary wooden hung windows, pass-through serveries, and interior sliding wooden partition sashes. Utilizing precision-wound constant-force stainless steel clockwork coil springs housed in heavy-duty nylon carrier blocks, this mechanism counterbalances sash weight effortlessly, allowing the movable window to hover securely at any open height without falling or slamming. Complete with dual cam flip sash locks, bottom tilt sliders, upper sash retainers, and optional extruded aluminum slide channels, it provides smooth, quiet vertical ventilation and positive security for residential windows, custom cafes, and servery bars.

Key Features

• Constant-Force Spring Hover Mechanism: High-tensile stainless steel spiral clockwork balance springs provide constant counteracting torque across the entire vertical stroke, holding the window firmly at any desired opening position.
• Architectural Wooden Frame Compatibility: Engineered specifically for wooden sash windows, custom pass-through counter sashes, and historic wood window restorations (compatible with sash leaf heights 350 mm – 900 mm and widths 350 mm – 1200 mm).
• Integrated Security Cam & Flip Locks: Includes a top-mounted central sash sweep lock and dual lateral flip locks (left and right handed) to draw the sliding sash tightly against the upper frame for weather-tight sealing and forced-entry deterrence.
• Wear-Resistant Nylon Slider Blocks: Self-lubricating engineering nylon slider shoes and guide retainers ensure low-friction, whisper-quiet vertical travel without wood-on-wood binding or jamming.
• Scalable Spring Capacity Models (4.5 kg – 18 kg): Modular spring mounting seats allow precise matching to window weight, from lightweight wooden sashes up to heavy double-glazed sashes:
  • Model 1 (Single Seat / 2 Springs): Rated 3 kg – 6 kg (Recommended sash weight: 4.5 kg / 10 lbs)
  • Model 2 (Dual Seat / 4 Springs): Rated 4 kg – 13 kg (Recommended sash weight: 9.0 kg / 20 lbs)
  • Model 3 (Triple Seat / 6 Springs): Rated 6 kg – 19 kg (Recommended sash weight: 13.5 kg / 30 lbs)
  • Model 4 (Quad Seat / 8 Springs): Rated 9 kg – 27 kg (Recommended sash weight: 18.0 kg / 40 lbs)
• Optional Heavy-Duty Aluminum Guide Tracks: Available as hardware-only balance packs or paired with 1-meter (39.4") extruded bronze-anodized aluminum slide tracks for clean recessed framing.

Technical Specifications

• Product Type: American-Style Vertical Sliding Sash Window Balance & Lock Hardware Kit
• Spring Material: High-Grade Tempered Stainless Steel Clockwork Spiral Springs
• Housing & Components: Heavy-Duty Engineering Nylon Carrier Bases, Die-Cast Zinc Alloy Window Locks & Latches
• Finish / Color: Matte Black Window Locks; Natural Bronze Springs; Sand Bronze Extruded Aluminum Track
• Sash Movement: Vertical Up-and-Down Sliding with Infinite Hover / Arbitrary Position Hold
• Applicable Window Dimensions:
  • Movable Window Width: 350 mm – 1200 mm (13.8" – 47.2")
  • Movable Window Height: 350 mm – 900 mm (13.8" – 35.4")
  • Side Frame Clearance Gap: Recommended 2 mm per side (sealing strip groove)
• Hardware Pack Contents: Balance Spring Assemblies (2, 4, 6, or 8 springs according to model), 2x Nylon Slider Shoes, 2x Stainless Steel Hook Plates, 1x Center Cam Sash Lock, 2x Side Flip Latches, and Mounting Screws
• Applications: Kitchen pass-through servery windows, residential single-hung and double-hung wooden windows, cafe bar service counter windows, and historical architectural renovations

Wholesale & OEM Capabilities

• Direct Factory Supply: Precision manufactured by Ningbo Dimon for window and door manufacturers, architectural millwork contractors, and building hardware distributors.
• OEM Customization: Custom spring tension ratings for non-standard glass thicknesses, customized sash lock designs and finishes (Brushed Brass, Antique Copper, White), and pre-cut aluminum track lengths.
• Export Packaging: Hardware components individually bagged and boxed in reinforced inner cartons with detailed dimensional installation templates; master export cartons palletized for international shipping.