1/2"-13 x 2" Hot Dip Galvanized Grade 2 / A307 Steel Coarse Thread Carriage Bolts 50PK A carriage bolt has a domed or countersunk head, and the shank is topped by a short square section under the head.
.Sheet Metal Screw, #8 x 3 in, 18-8 Stainless Steel Pan Head Phillips Drive, 100 PK A sheet metal screw has sharp threads that cut into a material such as sheet metal, plastic, wood, hard rubber, aluminum, and other comparable compositions.
.A coupling nut is a long nut tapped from each side to meet in the middle, rather than all the way through in the same direction, used to connect two threaded rods end to end.