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"

3/8-16 x 5 STRONG-BOLT® 2 Cracked and Uncracked Concrete Wedge Anchor 316 Stainless Steel(50)

9/16-12 x 1 Grade 5 Hex Cap Screw Plain Domestic USA (350)

5/8-18 x 3 1/2 Socket Cap Screw Alloy

7/8-9 x 2 3/4 Grade 8 Hex Cap Screw Plain Domestic USA (15)

5/16-24 x 2 Grade 5 Hex Cap Screw Zinc Plated Domestic USA (800) SDS Max Hammer Drill Bits The 3/8" anchor solution approved5 16 24 x 2 Grade 5 Hex Cap Screw Zinc Plated Domestic USA (800) . Grade 5 Hex Cap Screws are manufactured in the USA from medium carbon steel. Our Grade 5 material meets or exceeds SAE J429 Grade 5 specifications. All products are manufactured with rolled threads. Typical hardness on diameters 1 4 to 1 inch is HRC 25 34. On diameters over 1 inch to 1 1 2 hardness will range from HRC 19 30. Tensile strength for diameters 1 4 to 1 inch is a minimum of