The ULAMEX Adjustable Hook Handle for Trapeze is a height-adjustable stainless steel mounting bracket purpose-built for installing photovoltaic panels on trapezoidal metal sheet roofs. Manufactured from H17 stainless steel (1.4016 / AISI 430), this ferritic stainless hook accommodates sheet rib widths from 20 to 70 mm and features a compact 100 mm length with 2/4 mm thickness. Fastening is achieved with a bi-metal self-drilling screw that penetrates directly through the trapezoidal sheet into the substructure below — no pre-drilling required. The adjustable mechanism compensates for variations in sheet profile height, ensuring a level mounting plane for the PV rail across the entire roof area.
Technical Specifications
| Parameter | Value |
|---|---|
| Material | H17 stainless steel (1.4016 / AISI 430), ferritic |
| Height | Adjustable |
| Width range | 20–70 mm (fits standard trapezoidal profiles) |
| Length | 100 mm |
| Thickness | 2 / 4 mm |
| Fastening | Bi-metal self-drilling screw |
| Finish | Natural stainless (mill finish) |
| Roof type | Trapezoidal metal sheet |
| Service life | 25+ years |
Installation Guide
Position the adjustable trapeze hook on the high rib (crest) of the trapezoidal sheet at the planned attachment point. Align the hook so that the mounting rail connection point faces upward. Set the height adjustment to match the required rail level, accounting for sheet profile depth and any slope compensation needed. Drive the bi-metal self-drilling screw directly through the hook base and trapezoidal sheet into the purlin or substructure beneath — the bi-metal tip is designed to drill through the sheet metal without a separate pilot hole, while the stainless steel body resists corrosion at the penetration point. Apply an EPDM sealing washer under the screw head to prevent water ingress. Attach the PV mounting rail to the hook head using the appropriate bolt connection. Space hooks at intervals specified by the structural load calculation, typically every 1,000–1,500 mm along each rail line.
Roof Compatibility
The adjustable trapeze hook covers virtually all standard European trapezoidal sheet profiles with rib widths between 20 and 70 mm. This makes it compatible with trapezoidal sheets commonly found on warehouses, factories, agricultural buildings, logistics halls and commercial properties. Common profiles such as T-35, T-40, T-50, T-55 and T-70 are all within range. The hook mounts on the high rib of the sheet where structural strength is greatest. For corrugated (sinusoidal) profiles, verify that the crest width falls within the 20–70 mm range. The adjustable height mechanism accommodates different rib depths, so a single hook model serves roofs with varying sheet gauge and profile geometry.
Material Properties — H17 Stainless Steel
H17 (1.4016 / AISI 430) is a ferritic chromium stainless steel containing approximately 16–18% chromium. It provides good atmospheric corrosion resistance with a tensile strength of approximately 450 MPa. For trapezoidal roof applications, H17 is the preferred choice over austenitic grades because the hook is mounted on the external roof surface where cost-efficiency matters at scale, and the ferritic structure offers excellent resistance to stress corrosion cracking from thermal cycling. H17 is magnetic, which simplifies handling and positioning on metal roofs. The bi-metal self-drilling screw combines a carbon steel drill tip for penetration with a stainless body for long-term corrosion resistance at the critical sheet penetration point.
Why Choose ULAMEX
ULAMEX has supplied structural steel and stainless steel components for over 35 years, holding EN 1090 certification for the execution of steel and aluminum structures. As a B2B wholesaler, we deliver roof hooks, PV profiles, clamps, fasteners and ballast systems from a single source — reducing procurement complexity and ensuring component compatibility. European delivery with competitive wholesale conditions for solar installers, distributors and EPC contractors.
Frequently Asked Questions
Can I use this hook on corrugated (sinusoidal) metal sheets as well as trapezoidal?
Yes, provided the crest width of the corrugated profile falls within the 20–70 mm adjustment range. Position the hook on the highest point of the corrugation where the sheet has maximum rigidity. For very narrow corrugation crests, verify that the base plate sits securely before drilling.
Does the bi-metal self-drilling screw create a leak risk at the penetration point?
When installed correctly with an EPDM sealing washer under the screw head, the penetration is sealed against water ingress. The bi-metal screw is specifically designed for metal roofing — the stainless steel body prevents corrosion-induced loosening over time, which is the primary cause of leaks in screw-fastened metal roofs.
How many hooks do I need for a commercial trapezoidal roof installation?
The hook count depends on the module layout, rail span and the wind/snow load calculation per Eurocode EN 1991 for your site. As a starting guideline, space hooks at 1,000–1,500 mm intervals along each rail line, with 2 rails per module row. For large commercial roofs, a structural engineer should verify the hook spacing based on actual loads.