140mm is the fixed point for the RB3558's metal temple arm, matched to the aviator-style metal front this model uses. A compatible replacement has to hold that length precisely, since aviator-style fronts like this one show even a small mismatch as a visible tilt once worn.

The hinge screw is usually the first thing to loosen on a thin metal aviator temple like this one, long before the metal itself shows any real damage. A slightly wobbly arm at the pivot is a sign it's time for a replacement, not a sign the whole frame is worn out. A compatible 140mm aftermarket arm fixes that play directly and leaves the front and lenses untouched. A quick check of the hinge screw's tightness is worth doing first, since re-tightening sometimes resolves minor play without needing a new arm at all.

Frequently asked questions

Are these official Ray-Ban replacement parts?

These are compatible aftermarket arms, independently produced to match the 3558's hinge and 140mm 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 140mm arm includes its own hinge barrel, so if the wobble is coming from worn threading on the arm side of the 3558, 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 3558, matching its 140mm length and Aviator hinge design, so they attach to your existing screws and hinge without any filing or adjustment needed.

What material are the arms made from, and will the color match my frame?

The arms are molded in an acetate or metal finish that matches the Aviator style of the 3558 closely, though very slight shade variation is possible since they're independently produced as separate aftermarket parts rather than cut from the same batch as the frame.