Adding Rod Locks to Grado Headphones
You will need:
2 one-half inch (black or silver) hex cap screws with 10/24 thread (Lowes, Home Depot)
10/24 thread tap
5/32” drill bit
Removing the Rod blocks (the black plastic thingies marked “L” & “R”)
Mark the headphone cups “left” and “right” and remove them from the rod blocks.
Holding the Head Band near the rod block, rock the rod block front-to-back and then twist side-to-side. Some come off easy others need a little work, but they ALL come off.
Drilling the holes
With the rod blocks off, drill a 5/32” hole ½” deep in the center of the end of the block where the Rod hole is. Wrap masking tape around the drill bit to mark ½”. I use a small Drill Press for this step, it assures me of having a straight hole. A hand held drill will work fine, but do hold the block in a vise to help assure you don’t elongate the hole when drilling.
Thread the hole using the 10/24 thread tap.
Replace the Rod blocks on the headband, they usually fit tight. If they don’t a small drop Super Glue will fix the problem. Replace the cups and thread the cap screws in the newly drilled and tapped holes.