A coating machine for coating fiber yarns includes: a yarn supply device; a coating device including a tank, a drum rotatably disposed in the tank, and at least one annular groove formed circumferentially in an outer surface of the drum; a thickness adjuster disposed downstream of the coating device and including an adjuster support and at least one adjusting die mounted movably to the adjuster support, the adjusting die having a through hole, the through hole having an upstream inlet end and a downstream outlet end and being tapered from the upstream inlet end to the downstream outlet end; a shape-setting device disposed downstream of the thickness adjuster and having a heating unit controllable to operate at a predetermined temperature; a cooling device disposed downstream of the shape-setting device; and a yarn pick-up device disposed downstream of the cooling device.