5/16 USS Flat Washer Black Oxide N x LTH188 They have a domed head

They have a domed head with a square section under the head that prevents the bolt from turning when tightened

These heavy hex structural bolts are made of high-strength steel and are designed for use in structural applications

1-14 Fine Thread Finished Hex Nut Grade 5 Zinc is a versatile and durable fastener designed for secure connections in various applications

this bolt is suitable for use in decks

5/16 USS Flat Washer Black Oxide N x LTH188 They have a domed headThe 5 16 USS Flat Washer Black Oxide is a durable and reliable washer designed to distribute the load of a fastener evenly over a surface. Made from high quality steel, it features a black oxide finish that provides excellent corrosion resistance and a sleek appearance. With its standard 5 16" size, this washer is compatible with a wide range of bolts and screws. Its flat design allows for a secure and stable connection, preventing the fastener from