1 2 13 X 1 1 2 Hex Head Cap Screw 2024 T4 Aluminum 205 Finish Package (50) Strong Drive SD Connector Screws Type 316 Stainless Steel 1 2 13 x 4 Socket Head 1 2 13 x 4 Socket Head Cap Screws Thermal Black Oxide Alloy Steel Domestic USA Package (25) Socket Cap Screws with Thermal Black Oxide finish are made in the USA from durable alloy steel for superior strength and reliability These metric locknuts feature nylon inserts that create a strong gripping power meaning they are reliable and safe for use these screws provide reliable performance and are conveniently packaged in a quantity of 50 ideal for aerospace and high performance applications where reducing weight is crucial without sacrificing durability