Steel/zinc. Mini-box packaging. No. 370827: Diameter: 3/8", Overall Length: 1-7/8", Head Type: Hex Nut, Finish: Zinc, Pkg Qty: 25, Package Type: Box No. 370828: Diameter: 3/8", Overall Length: 3", Head Type: Hex Nut, Finish: Zinc, Pkg Qty: 20, Package Type: Box No. 370830: Diameter: 1/2", Overall Length: 3", Head Type: Hex Nut, Finish: Zinc, Pkg Qty: 12, Package Type: Box No. 370831: Diameter: 1/2", Overall Length: 4", Head Type: Hex Nut, Finish: Zinc, Pkg Qty: 10, Package Type: Box