hardness will range from HRC 31-39

3/4-16 x 5 1/2 Grade 8 Hex Cap Screw Yellow Zinc Plated

1/2-13 x 7 Grade 8 Hex Cap Screw Yellow Zinc Plated

1-8 x 5 1/2 Grade 8 Hex Cap Screw Yellow Zinc Plated

1-8 x 9 Grade 8 Hex Cap Screw Yellow Zinc Plated

7/8-9 x 4 1/2 Grade 8 Hex Cap Screw Yellow Zinc Plated 5/8-11 Grade 8 Hex Cap Screws Yellow Zinc Plated hardness will range from HRC7 8 9 x 4 1 2 Grade 8 Hex Cap Screw Yellow Zinc Plated . Grade 8 Hex Cap Screws are manufactured 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 2 1 2 inches