Product Name: Heavy Hexagon Nuts
Type: Heavy Hex Nut
Design Standard: ASME B18.2.2
Material: ASTM A194 Grade 8M, Stainless Steel
Size: 5/8 Inch
Source: https://www.landeepipefitting.com/heavy-hexagon-nuts-asme-b18-2-2-astm-a194-grade-8m-5-8-in.html