the hardness rating is HRC 24-35

1/4 x 1 Nailon™ Anchor Mushroom Zinc Plated (100)

1-8 x 2 1/2 Grade 8 Hex Cap Screw Plain Domestic USA (10)

10 x 2 1/2 Simpson Bugle-Head Wood Decking Screws - 6-Lobe Drive 316 SS - 1 lbs Pack (82)

1-8 x 5 Hex Cap Screw SS 18-8 (A2)

3/8-24 x 3 1/2 Grade 5 Hex Cap Screw Zinc Plated Domestic USA (50) 9/16-12 Grade 8 Hex Cap Screws Plain - Domestic USA the hardness rating is HRC3 8 24 x 3 1 2 Grade 5 Hex Cap Screw Zinc Plated Domestic USA (50) . 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