The socket head cap screws are 100% stainless steel 304 (A2-70) which offers a high level of chemical and corrosion resistance. | Thread Diameter: 6 mm; Thread Size: 1.0 mm; Thread Length: 10 mm, 12 mm, 16 mm, 20 mm, and 25 mm. | Drive Type: Allen Hex Socket 4 mm; Color: Bright Finish. | Package Included (NOTE Total Length for Flat Head Socket Screws): M6 x 10mm (10 PCS), 12mm (10 PCS), 16mm (10 PCS), 20mm (10 PCS), 25mm (10 PCS), and all come in a quality plastic storage box. | Flat Head Socket Screws are great to have around for use in wood and wet environments.