Grade Identification Markings
Grade Identification MarkingSpecificationMaterialNominal Size, In.Proof Load Stress, ksiHardness RockwellSee NoteMinMax
No Mark ASTM A563 Grade O Carbon Steel 1/4 - 1-1/2 69 B55 C32 2,3
ASTM A563 Grade A Carbon Steel 1/4 - 1-1/2 90 B68 C32 2,3
ASTM A563 Grade B Carbon Steel 1/4 - 1 120 B69 C32 2,3
>1 - 1-1/2 105
ASTM A563 Grade C Carbon Steel, may be and Tempered 1/4 - 4 144 B78 C38 4
ASTM A563 Grade C3 Atmospheric Corrosion Resistant Steel, may be and Tempered 1/4 - 4 144 B78 38 4,6
ASTM A563 Grade D Carbon Steel, may be and Tempered 1/4 - 4 150 B84 C38 5
ASTM A563 Grade DH Carbon Steel, and Tempered 1/4 - 4 175 C24 C38 5
ASTM A563 Grade DH3 Atmospheric Corrosion Resistant Steel, and Tempered 1/4 - 4 175 C24 C38 4,6