Especially useful in metal-to-metal or where heavy duty fastening is required.70 x 12 mm Phillips Pan Machine Screw, Zinc Plated Steel, 25 PK Commonly used with flat or lockwashers. Machine screws are used in fastening nearly all types of hard materials..
Sheet Metal Screw, #6 x 3/16 in, Zinc Plated Steel Pan Head Phillips Drive, 50 PK Sheet metal screws make excellent fasteners for attaching metal hardware to wood because the fully threaded shank provides good retention in wood..
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..