5/8" to 1/2" x 1-1/2" Hot Dip Galvanized Steel Coupling Nuts (25 pcs.)

Diameter: 5/8"
Diameter 2: 1/2"
Length: 1-1/2"
Material: Steel
Finish: Hot Dip Galvanized
Driver Type: 13/16" Wrench
Style: Reducer
Type: Coupling Nut

Box of 25.

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.