S-5-USF™ Mini Clamp

The answer to this question varies with the load direction, the seam profile, the roof material and the clamp model.

These variables result with a wide range of holding capacities from ±300 lbs (235 kg) to ±4,000 lbs (1800 kg). This is why for critical applications it is important to correctly identify the roof panel, seam type, gauge, etc along with the recommended seam clamp for the specific roof.  [ link-- Clamp-to-seam tool]  When used on some “applied cap” architectural type seam styles, S-5! may yield low load-to-failure results as compared with integrated seam profiles. Always check our load table to verify the correct allowable holding strength on your specific roof type.

We would never promote a product that solves one problem on a metal roof while creating another. The metallic coatings on steel sheet are very thin but very important for corrosion protection of the base steel. They must not be breached. That’s why we created our custom-designed, stainless steel setscrew. We went to great lengths to have these setscrews custom made to our exact specifications before ever taking our products to market. This special screw has a polished rounded end to prevent damage to the protective coatings of steel sheet. But we didn’t stop there.

These round-point setscrews (or oval-shaped point on one end) are shaped to a specific radius and polished to eliminate abrasion to the panel finish when tensioned. But we didn’t stop there either. We have also performed 2000 hour ASTM B-117 Salt Fog testing on our clamps and setscrews, attached to Galvalume® coated steel panels to prove they maintain perfect metals compatibility and cause no mechanical damage to the coating. 

Although standard “cup point” setscrews are lower in cost, they should never be used on coated steel (as some of our competitors may claim). The cup point digs through the coating, creating a corrosion site. 

In addition, all our related hardware is non-corrosive, 300 series stainless, not plated steel. The unique S-5! round-point setscrews are always furnished with our clamps because they offer a secure mechanical connection while protecting roof warranties. 

For more information on this subject, please visit The Truth about Setscrews.            

Our standard test procedures are to test the mini (one setscrew) clamps with negative load normal to seam, and standard (two setscrew) clamps with load parallel to seam. We have performed numerous parallel to seam datum tests on mini clamps and concluded from engineering analysis the mini clamp is (conservatively) obtaining more than ½ the strength of the standard clamps. In fact, the majority of the datum testing indicates the strength of a mini is closer to 2/3 the strength of a standard clamp. In due course, we are adding certified lab testing in this load direction for mini clamps.

In the interim, should certification of the load application parallel to seam be critical to your application, we suggest using the standard (two setscrew) design.

S-5! clamps will not fit on face-fastened trapezoidal rib or corrugated type panels. While our clamps won't work on thru-fastened roofs, we do have bracket products for them. Explore our entire line of brackets.

S-5! products will not fit to hollow “batten” seam type panels (see images in red below) - but can be used for the traditional (wood-backed) batten seam folded joints, as shown below in green.

Any time there is a folded seam we can usually attach a clamp to it. A great way to know if we have a product for your roof is to determine what the roof is with our "Clamp-to-Seam tool".