The FR1NR3SB is a hardened steel locking nut for the Floyd Rose 1000 Series tremolo system, finished in satin black. Its job is to clamp the strings at the headstock end so tuning changes at the tuners have no effect on pitch once the clamps are tightened down. If your existing nut is cracked, stripped at the clamp screws, or corroded to the point where clamping pressure is uneven, this is a direct replacement.

Fit is decided by two things: the width of your nut slot and the radius of your fretboard. Floyd Rose sizes its locking nuts across a range — R2, R3, R4 and others — and this part is an R3. Too flat a radius and the outer strings sit proud of the clamping surface and buzz. Too narrow and the strings crowd the fretboard edge. Neither problem goes away with setup tweaks. Measure the nut slot width and check the fretboard radius on your current nut before ordering. Do not rely on the guitar model name alone — the same model has shipped with different nut sizes across production runs.

The nut is hardened steel. That matters because the clamping blocks bear direct string tension at the lock point; a softer material wears faster at the saddle contact and the screw threads. The satin black finish matches standard 1000 Series hardware.

If you are not certain this is the right size for your guitar, send us the make, model and year and we will check it against what we have on the bench.