The 3/8" anchor solution approved for 3 ¼" concrete thickness: The Strong-Bolt 2 anchor can be installed in cracked concrete with a minimum thickness of 3 ¼"

1/4-20 x 3 Grade 8 Hex Cap Screw Plain Domestic USA (750)

#16 Heavy Duty Drill Bit - Stubby Length

7/16-20 x 2 1/4 Grade 8 Hex Cap Screw Plain Domestic USA (350)

9/16-18 x 4 Grade 8 Hex Cap Screw Plain Domestic USA (25) Square Bugle Decking Screws Yellow Zinc Plated The 3/8" anchor solution approved9 16 18 x 4 Grade 8 Hex Cap Screw Plain Domestic USA (25). 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