Fasteners for Curtain Walls & Facade Systems
A facade fixing package has to carry wind and dead load, allow installation tolerance, and resist corrosion for the life of the building. Huilang supplies cast-in channels and T-bolts for bracket adjustment, stainless and coated bolts for framing connections, and embedded plates for heavy facade zones.
Fastener types for curtain wall systems
Cast-in channels for brackets
C-profile channels cast into the slab edge or column, giving the facade bracket a continuous adjustable fixing line.
Channel specification →Stainless and coated fixings
A2-70 / A4-80 stainless bolts and zinc-flake coated bolts for mullion, transom and bracket connections.
Bolt options →Embedded plates
Anchor plates and welded bars for heavy facade zones, canopies and stone-cladding supports.
Embedded parts →Facade fasteners have to absorb movement
A curtain wall is a lightweight envelope fixed to a concrete or steel frame. It carries wind load, thermal movement, seismic drift and its own dead load, and it must remain watertight and visually aligned for decades. The fasteners connect the adjustable bracket to the structure and the framing members to each other; they are the parts that allow the facade to be set out and then locked.
- Thermal movement. Aluminium framing expands and contracts with temperature; connections must allow movement without loosening.
- Wind and seismic load. Brackets and anchors transfer horizontal load into the slab edge; the fixing system has to be designed for the project loads.
- Site adjustment. Facades are set out to tolerance; slotted or channel-based fixings let the installer adjust before final tightening.
- Corrosion and appearance. Exposed fixings and stainless components must not stain the facade or create bimetallic corrosion with aluminium.
Fasteners by facade interface
| Interface | Typical Huilang item | What the buyer should define |
|---|---|---|
| Slab edge to bracket | Cast-in C-profile channel with T-bolt, or embedded plate | Profile, anchor studs, slot filler, bracket drawing, adjustment range |
| Bracket to mullion | Stainless or coated hex bolts, grade 8.8 / A2-70 / A4-80 | Diameter, length, material, isolation washers and torque |
| Mullion to transom | Self-drilling or machine screws, bolts and nuts | Material compatibility with aluminium and the required fixing standard |
| Canopy, stone or heavy cladding | Embedded plate with welded anchor bars | Plate and bar schedule, weld detail, coating and anchor design |
| Fire-stop and perimeter zones | Anchors, brackets and bolts | Fire-rated fixing detail and project documentation |
Cast-in channels for facade brackets
Facade brackets are set out after the concrete frame is complete, when the actual slab tolerance is known. A continuous cast-in channel lets the bracket position be adjusted along the edge and avoids drilling reinforcement or casting in dozens of individual plates.
- Choose the slot filler. A filled profile keeps concrete out and is removed before the bracket is installed; specify it with the channel.
- Match T-bolts to the channel. Slot width and tooth pitch must suit the T-bolt; a mismatched pair can slip under wind load.
- Check the anchor studs. Stud diameter, spacing and length depend on the slab edge, cover and bracket load.
- Plan the cutting list. Corners, movement joints and slab steps require cuts and end caps; producing them off-site keeps the facade programme on track.
Stainless, coated and isolated fixings
Aluminium framing, stainless bolts and galvanized brackets create a range of galvanic pairs if they are connected directly. Where exposed fixings are specified, state the material and whether isolation washers or sleeves are required. A2-70 is common for general facade use; A4-80 or A4-70 is used for coastal or higher-chloride environments.
| Item | Typical specification | Notes |
|---|---|---|
| Stainless bolts and machine screws | A2-70, A4-70, A4-80 | Confirm grade, strength and whether the part is visible |
| Zinc-flake coated bolts | Class 8.8 / 10.9 with zinc-flake coating | Controlled friction coefficient and good corrosion resistance |
| Hot-dip galvanized brackets | Galvanized steel, coating thickness per project | Thread allowance after galvanizing and re-tapping |
| Isolation washers and sleeves | Nylon or EPDM, sized to the bolt | Separates dissimilar metals and reduces staining |
Tolerance, adjustment and final lock
The facade bracket is usually installed with some adjustment in all three directions. Channels and slots allow that adjustment, but the connection has to be designed so it can be locked without relying on friction alone once the position is set.
- Use serrated or hardened washers. They provide a reliable locking surface on slotted connections.
- Confirm the torque. Stainless and coated bolts have different friction behaviour; use the torque specified for the actual material.
- Control the shim stack. Packing and shims should be specified and inspected so the bracket does not rely on an uncontrolled gap.
- Protect exposed stainless. Clean off mortar and construction debris promptly to avoid staining the facade.
Inspection and documentation
Facade fixings are inspected for dimensions, thread, material grade and coating. Stainless fasteners should carry grade marking; galvanized parts should be checked for coating thickness and thread condition. Material certificates, test reports and packing lists are supplied with the goods, and third-party testing can be arranged where the project requires it.
What to send for a curtain-wall fixing quotation
| Information | Why it is needed |
|---|---|
| Facade bracket drawing | Defines channel, plate, bolt size and adjustment range |
| Slab edge or column detail | Sets cast-in position, anchor studs and concrete cover |
| Material and grade | Stainless A2/A4, class 8.8 or 10.9, isolation requirement |
| Coating and appearance | Galvanized or zinc-flake; visible or concealed parts |
| Project standard and testing | Material certificates, salt-spray and third-party reports |
| Quantities by elevation or delivery stage | Supports staged delivery to match the facade programme |
Send a drawing or specification for quotation
Include the interface, material, grade, coating, quantity and delivery stage. We will confirm feasibility, tooling where needed, documents and lead time before quoting.
Tel / WhatsApp / WeChat: +86 185 3100 8199
Email: sales@huilang.top
Related applications
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FAQ
- What fasteners are used for curtain wall brackets?
- Facade brackets are commonly fixed to cast-in C-profile channels with T-bolts, or to embedded plates. Channels allow adjustment along the slab edge; plates give a fixed, high-capacity connection for heavy zones.
- Why use cast-in channels instead of drilled anchors?
- Channels give a continuous slot that allows the bracket to be positioned after the concrete is complete, without drilling reinforcement or casting in many individual plates. They also avoid site dust and drilling time.
- Which stainless grade should be used on a facade?
- A2-70 is common for general facade fixings. A4-70 or A4-80 is used for coastal, high-chloride or chemically exposed locations. Confirm the grade and whether isolation washers are required against aluminium.
- How do you prevent bimetallic corrosion?
- Specify the correct stainless grade, avoid direct contact between dissimilar metals where the design allows, and use isolation washers or sleeves. Keep the fixing detail consistent across the facade package.
- Can you supply the channel, T-bolts and brackets as one package?
- Yes. Supplying the channel, T-bolts, brackets and cutting list together avoids slot and tooth-pitch mismatch, which can cause slipping or installation delay.
- What documents can be supplied for a facade order?
- Material certificates, dimensional and coating inspection records, stainless grade marking and packing lists with batch identity are supplied. Third-party salt-spray or mechanical testing can be arranged on request.