while the #2 square drive makes them easy to fasten

1/4 x 2 1/4 Slotted Hex Hi-Low Thread Concrete Screws Blue Ceramic Coated (1500)

7/8-14 x 2 Grade 5 Hex Cap Screw Zinc Plated Domestic USA (15)

With its useable length of 5 inches

7 x 1 5/8 Simpson Trim-Head Self-Drilling Siding Screw - Square Drive 410 SS - Box (100)

1/4 x 3/4 Simpson Zinc Nailon™ Pin Drive Anchor Mushroom Head Carbon Steel Pin (100) L9 Hex Nuts Alloy Cadmium Yellow and Wax Coated - Domestic USA while the #2 square driveSimpson Zinc Nailon Pin Drive Anchors feature a mushroom head style and a carbon steel pin. This 100 pack includes 1 4 X 3 4 inch anchors that have been tested for exceptional performance and durability. Ideal for masonry and concrete applications.