The ULAMEX Hook Handle for Standing Seam Sheet is a non-penetrating stainless steel clamp designed for mounting photovoltaic panels on standing seam (Stehfalz) metal roofs. Unlike tile-based roof hooks, this clamp grips the raised seam fold of the metal roof without drilling, screwing or otherwise penetrating the roofing material — preserving the roof’s watertight integrity and manufacturer warranty. Manufactured from H17 stainless steel (1.4016 / AISI 430), the clamp measures 40 mm wide and 90 mm long with a 3/4 mm thickness, and is secured with an included M10 DIN 933 metric bolt.
Technical Specifications
| Parameter | Value |
|---|---|
| Material | H17 stainless steel (1.4016 / AISI 430), ferritic |
| Width | 40 mm |
| Length | 90 mm |
| Thickness | 3 / 4 mm |
| Fastening | M10 DIN 933 metric bolt (included) |
| Mounting method | Non-penetrating seam clamp |
| Finish | Natural stainless (mill finish) |
| Roof type | Standing seam (Stehfalz) metal roofs |
| Service life | 25+ years |
Installation Guide
Position the seam clamp over the raised seam fold at the planned mounting point. Open the clamp jaws wide enough to straddle the seam, then slide it down until the clamp body sits firmly against the seam base. Tighten the M10 DIN 933 bolt with a torque wrench to the specified torque value — this compresses the clamp jaws around the seam fold, creating a friction-locked connection. The clamp grips the seam without piercing the roof sheet, so no sealant or waterproofing is required at the attachment point. Attach the PV mounting rail to the upper connection point of the clamp. Space clamps along the seam at intervals specified by the structural load calculation, typically every 600–1,000 mm. Always install clamps on at least two parallel seams per rail line for lateral stability. Check that the clamp does not deform the seam fold beyond its elastic limit — over-tightening can damage the roofing material.
Roof Compatibility
This clamp is designed for standing seam (Stehfalz) metal roofs — a roofing type widely used on commercial, industrial, agricultural and modern residential buildings across Europe. Standing seam roofs are characterised by raised vertical seams that connect adjacent sheet panels without exposed fasteners. The ULAMEX seam clamp is compatible with standard European seam profiles up to 4 mm material thickness. It works on both single-fold and double-fold standing seams, as well as snap-lock and mechanical seam profiles. The non-penetrating design is the preferred mounting method specified by most standing seam roof manufacturers, as it preserves the roof warranty by avoiding any holes in the roofing material. For trapezoidal or corrugated metal roofs (which have a different profile geometry), use the adjustable trapeze hook instead.
Material Properties — H17 Stainless Steel
H17 (1.4016 / AISI 430) is a ferritic chromium stainless steel with 16–18% chromium, providing good atmospheric corrosion resistance and a tensile strength of approximately 450 MPa. For standing seam clamps, H17 is chosen because the clamp is exposed to outdoor conditions (unlike tile hooks which are concealed beneath the roof covering), yet the ferritic grade provides sufficient corrosion resistance for most inland and suburban environments at a competitive cost point. The ferritic structure also delivers superior resistance to stress corrosion cracking from the thermal expansion and contraction cycles that metal roofs undergo daily. For coastal installations, consider specifying V2A (1.4301) or V4A (1.4404) clamps — contact ULAMEX for availability.
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
Does the seam clamp void my standing seam roof warranty?
No. The seam clamp is a non-penetrating solution that grips the raised seam fold without drilling or screwing through the roofing material. Most standing seam roof manufacturers specifically recommend clamp-based PV mounting to preserve the roof warranty. Always verify with your roof manufacturer’s specific warranty terms.
What torque should I apply to the M10 bolt?
The recommended tightening torque depends on the seam material and thickness. As a general guideline, 20–25 Nm is suitable for standard steel standing seams. Do not over-tighten, as this can deform the seam fold beyond its elastic limit. Always use a calibrated torque wrench and follow the PV system manufacturer’s specifications for your specific installation.
Can I use this clamp on a zinc or copper standing seam roof?
The H17 stainless steel clamp is compatible with galvanised steel, aluminium and most coated steel standing seam roofs. For zinc (Titanzink) or copper roofs, galvanic corrosion between dissimilar metals must be considered. Use an intermediate EPDM or neoprene isolating pad between the clamp and the seam to prevent direct metal-to-metal contact. Contact ULAMEX for technical guidance on specific material combinations.