Top quality, high pull out strength and ease in setting:
• Cap Screws: For 8, 10, 16 & 25mm are 410 Stainless Steel Trilobular Screws, with Silver Stalgard® corrosion resistance finish.
#2 Phillips-Sq . Out of round tip for swift threading into screw race (receiver). Hurricane Strong! – #10-32 thread grabs at 4th thread, 1/16″ from tip.
Pre-Drill Cap – Self Tap Screw engages, even when screw at slight angle. – Tip Design 
Cap seals tight. Min. roof pitch 5º or 1/12 pitch. – Silver Stalgard® chrome-free multi-step coating process that combines an inorganic zinc-rich base coat with aluminum-pigmented organic topcoat. The base coat provides protection of steel substrate while thermosetting topcoat creates a durable barrier. This duplex process offers barrier corrosion protection to provide exceptional corrosion resistance. Salt Spray at 1000+ hours with no rust!
• Base Screws: For Wood – #8×1-5/8″ Tan Deck Type – Corrosion Resistant, even with pressure treated lumber, 1-1/8″ penetration into wood, for high pull out strength.
• Base Screws: For Metal – #410 stainless. Type 3 drill point. Max .210″ steel or aluminum.
• Screws for Body of the Sheet: #12 x 2″ (for 8-16mm polycarbonate) & #12 x 2.5″ (for 25mm polycarbonate) 18.8 Marine Grade Stainless Steel, Hex Washer Head Screws, with Hi-Low Threads and Type ’17’ chisel point. Threads offer high pull out strength of 700+ pounds, when embedded 1″ onto typical fir or pine dimensional lumber. Type ’17’ chisel point swiftly and effectively penetrates into the wood.
18.8 Stainless Steel Marine Grade 3/4″ Washers
Wood – Depth Embedded with washer: • 2″ Screw – 8mm (1.5″), 16mm (1.25″) • 2.5″ Screw – 25mm (1.35″)