Rachias timbo is a mygalomorph spider of Argentina, named after its type locality: El Timbó, Iguazú, Misiones.

[2] R. timbo differs from Brazilian Rachias species (with similar genitalia) by being smaller and having lower keels on the male embolus.

Total length of the male paratype was 16.50 millimetres (0.650 in).

Chelicerae: rastellum formed by strong, thick but long and attenuate setae.

Its inner margin had 10 or 11 small, widely spaced teeth.