Proper Fastener Selection Matters

Proper fastener selection is essential for maximum holding strength. Drill point and thread design should match the thickness of the material being fastened. A screw with an oversized drill point on thin-gauge steel reduces thread engagement, weakening the connection, while an undersized drill point on heavy steel won’t seat or bite properly.

Koop Sheet Metal offers a wide range of metal and wood fasteners, but two of our most-used metal fasteners are the Stitch Screw and the Standard 3/16″ Roofing Screw.

Why We Recommend Stitch Screws for Hat Channel

Stitch Screws are a shorter, specialized metal-to-metal fastener with a smaller drilling bit designed specifically for joining two layered sheets of metal to each other.

Our Hat Channel, available in 20 gauge and 18 gauge, provides an excellent batten system for roofing applications.

When installing R-Panel roofing over 18g or 20g Hat Channel, we recommend using Stitch Screws. Because these gauges are thinner than our other structural framing members, Stitch Screws provide a more suitable fastening solution.

Standard roofing screws feature a larger drill point designed for fastening into heavier-gauge steel. When used on thinner Hat Channel, they can remove more metal than necessary, leaving less material for the threads to engage securely.

Stitch Screws create a smaller hole, allowing for improved thread engagement and a tighter, more secure connection between the roofing sheet and the Hat Channel.

R-Panel + Hat Channel (18g & 20g)

Recommended Fastener: Stitch Screws

• Creates smaller hole in thin-gauge steel
• Leaves more steel around the threads for improved thread engagement
• Delivers a stronger, more secure grip between the roofing sheet and Hat Channel

R-Panel + Heavy Steel Framing (C-Purlins, 14g Tubing)

Recommended Fastener: Standard 3/16″ Roofing Screws

• Larger drill point designed to penetrate heavier-gauge steel
• Ensures full thread engagement into thicker material
• A Stitch Screw’s smaller point won’t drill through thicker gauge or harder steel framing as reliably as the bigger point on the standard screws