When it comes to selecting premium aluminum sliding doors for residential or commercial projects, the SL155 and SL112 series from ALPES stand out as two of the most capable options on the market. Both are engineered with 6060-T66 aluminum profiles and thermal break technology, but they serve different design priorities and project requirements. In this guide, we break down the key differences to help you decide which model best fits your needs.
The SL155 Thermal Break Sliding Door is ALPES' flagship four-track system designed for maximum opening area and panoramic views, while the SL112/167 Multi-Functional Heavy-Duty Sliding Door offers flexible track configurations (single, two-track, or three-track) with a focus on heavy-duty performance and versatility. As a leading sliding door supplier, ALPES has engineered both series to meet international building standards with premium German hardware partners.
| Specification | SL155 Thermal Break | SL112/167 Heavy-Duty |
|---|---|---|
| Profile Grade | 6060-T66 | 6060-T66 |
| Profile Thickness | 2.2 – 2.5mm | 1.8 – 2.5mm |
| Frame Wall Width | 155mm (Four Track) | 112mm / 167mm (1-3 Track) |
| Glass Sash Thickness | 54.5mm | 43mm |
| Sash Width | 44.5mm | 53mm / 75mm |
| Insulation Strip | PA66GF25 (Thermal Break) | PA66GF25 (Thermal Break) |
| Max Sash Load | 400kg (20-wheel system) | 220kg per sash |
| Max Opening Area | Up to 7.5m² per sash | Configurable per track layout |
The SL155 is built around a four-track 155mm frame that delivers one of the widest opening areas in ALPES' catalog. With a single sash reaching up to 2800mm wide and 2600mm tall, it can open up to 7.5 square meters — ideal for luxury villas and high-end commercial spaces that demand unobstructed panoramic views. Its recessed sash design creates a tighter seal and better stability, while the integrated flush-mounted handle maintains a sleek, uninterrupted visual line.
What truly sets the SL155 apart is its 20-wheel self-balancing pulley system that supports up to 400kg per panel. This heavy-duty mechanism ensures effortless gliding even with oversized glass panels, making it a top choice for thermal break sliding door installations in grand living rooms, sea-facing balconies, and resort-style properties.
The SL112/167 series is defined by its flexibility. Available in single-track (112mm), two-track (112mm), or three-track (167mm) configurations, it adapts to a wide range of architectural requirements — from compact apartment balconies to expansive patio openings. The frame-enclosing-sash structure interlocks for reinforced rigidity, while the 45mm high-ｄｒｏｐ bottom track ensures instant drainage even during heavy downpours.
As a versatile option from a trusted sliding glass door manufacturer, the SL112/167 supports numerous customization options including glass railings, inward-open mesh screens, and rolling mesh systems. Its 220kg per-sash driving capacity and 24A insulated glass make it well-suited for mid-to-large scale residential projects where versatility and cost-effectiveness are key priorities.
Both models utilize PA66GF25 thermal break strips to minimize heat transfer, delivering substantial energy savings compared to non-thermal break aluminum doors. The SL155 features a dual-matrix eight-layer sealing system combined with a four-sealing design that provides all-weather waterproofing and sound insulation. The SL112/167 employs a mechanical sealing system with a window sash sink design that effectively blocks wind and rain infiltration.
For drainage, the SL155 uses a passive check valve system that accelerates water removal while preventing backflow — a sophisticated solution for regions with intense rainfall. The SL112/167 relies on a 45mm high-ｄｒｏｐ bottom track with an optional 85mm high water barrier, offering reliable drainage at a more accessible price point.
Both series are built with security in mind. The SL155 features a multi-point locking design with stainless steel locks housed in precision-cast reinforced casings, while the SL112/167 includes optional screen mesh systems for added insect protection and security. All ALPES doors use top-tier hardware from renowned German brands, ensuring long-term reliability and smooth operation.
Both the SL155 and SL112/167 represent exceptional craftsmanship from ALPES, a manufacturer with a 100,000 m² production base and facilities in Foshan and Zhaoqing. The SL155 is the clear choice for projects where maximum glass area, ultra-smooth operation, and top-tier sealing performance are non-negotiable. The SL112/167 shines when project flexibility, configurable track layouts, and balanced performance-to-cost ratio are the priorities.
To explore both series in detail or request custom specifications, visit the ALPES sliding door collection or contact their team directly for project-specific consultation.
