Flat Head Socket Cap Screws are used for flush mounting of sections

7 x 2 1/4 Simpson Trim-Head Self-Drilling Siding Screw - Square Drive 410 SS - Carton (4000)

12 x 2 Simpson Flat-Head Self-Drilling Screw w/ Wings - Square Drive 410 SS - Carton (1000)

Galvanized nuts are over tapped per ASTM A563

9/16-12 x 3 Grade 8 Hex Cap Screw Plain Domestic USA (150) Phillips Pan-Head Marine Screws 316 Stainless Steel Flat Head Socket Cap Screws9 16 12 x 3 Grade 8 Hex Cap Screw Plain Domestic USA (150). Grade 8 Hex Cap Screws are manufactured in the USA from medium carbon alloy steel. In diameters 1 4 to 1 1 2 inches our Grade 8 material meets or exceeds SAE J429 Grade 8 specifications. Diameters over 1 1 2 inches meet or exceed ASTM A354 Grade BD. All material is manufactured with rolled threads. Yellow zinc plated bolting will meet or exceed ASTM F1941. Typical hardness on diameters 1 4 to