This is for one package of one hundred (100) quality marine grade stainless steel (AISI 316) 3/8"-16 x 1" UNC Hex Head Cap Screw Bolts. These are an imperial thread, and require an imperial UNC nut. This bolt is passivated for a better finish and also makes the bolt more resistant to corrosion. Not to be used for overhead lifting. This bolt meets the American Society of Mechanical Engineers ASME B18.2.1 and the American Society for Testing and Materials ASTM F593 specifications. It has six flat sides that a wrench can grip to turn from the side, enabling use for when there is no space above the bolt. Bolts are externally threaded fasteners that are used with nuts to connect components. AISI 316 stainless is a premium grade of stainless and is considered by many to be best in class. 316 stainless is corrosion resistant and very durable even in the harshest of conditions.