Specifications: The Carbon Steel Grub Screw, with hexagonal head, is made of high strength 12.9 Grade carbon steel. Its oxidation surface provides good resistance to extension and corrosion in various environments. This hexagonal head screw is multipurpose and can be easily handled with a hex key. Ideal for use in confined areas such as fastening components, industrial and construction fasteners. Screw size and quantity: M12*16mm, 10 pieces. Note: Please allow 1-3 mm errors due to manual measurement. Thank you for your understanding. Keep away from children and babies and avoid swallowing.