RB3556 and its RB3556N sibling share the same eight-sided front and 145mm metal arm length, the 'N' marking a finish variant rather than a different build. This compatible pair is cut to that shared spec, with the hinge angled for the octagonal front's sharper corners rather than a round or square one.

Because an octagonal front meets the arm at a tighter corner than a rounder frame does, the hinge joint on this shape tends to show play sooner than it would on a round-metal pair of the same age — that's simply a function of the geometry, not a weaker build. Tightening the hinge screw is the first thing to try; if the joint itself has worn loose, replacing the arm resolves it for good. Either fix is quick, since neither one involves touching the octagonal front or the lenses it holds.

Frequently asked questions

Can I replace just one arm, or do I have to buy both?

You can order a single side if only one arm on your 3556 is broken or scratched, or buy the pair if both need replacing — either way they match the 145mm length exactly.

Are these official Ray-Ban replacement parts?

These are compatible aftermarket arms, independently produced to match the 3556's hinge and 145mm length. They aren't manufactured or supplied by Ray-Ban, just built to the same measurements so they attach correctly.

My hinge feels loose — will new arms fix that, or is it the frame that's worn?

A new 145mm arm includes its own hinge barrel, so if the wobble is coming from worn threading on the arm side of the 3556, replacing it usually restores a snug, tight fold.

How do I know these arms will fit my Ray-Ban frame?

These arms are made specifically for the 3556, matching its 145mm length and Irregular hinge design, so they attach to your existing screws and hinge without any filing or adjustment needed.