A plumb bob is a balanced weight with a sharp point on one end and an attachment point for a cord on the other. Properly tying the knot in the cord to secure the plumb bob will ensure that the plumb bob functions correctly. Before tying the knot, it is important to understand the terminology used for the cord. The tag line refers to the end of the cord that you inserted into the plumb bob. The standing line refers to the long length of cord that will suspend the plumb bob. Determine if your plumb bob has a removable cord attachment by examining the cord attachment end of the plumb bob. If you see a small cord sized hole on top of the plumb bob, unscrew the cord attachment. Wet your fingers and rub the end of the cord between your fingers to pull any fraying strands of line tight to the cord. Insert the cord into the cord hole. Pull the line through the hole so you can grasp the tag line with your fingers. If you have a one-piece plumb, insert the tag line until you can see the line in