Knurled screws for fingertip fine tuning of individual strings on a Floyd Rose® tremolo. Repair techs should keep a few on hand to replace lost or stripped originals.
#1551 thread is M5 x 0.8 thread and is the screw installed in the Schaller Floyd Rose, and also fits the original Floyd Rose and Floyd Rose II. It won't fit our Double-Locking Tremolo.
#2119 thread is M4 X .7 and is the screw installed in our Double-Locking Tremolo. It will not fit a Floyd.