Abstract: An expansion jaw assembly for use in expanding an end fitting within a fluid hose comprises a plurality of elongated jaw elements configured when combined to form a cylindrical body sized for introduction into the interior of the end fitting. The jaw elements when combined define a tapered bore for receiving an expansion pin to move the jaw elements radially apart relative to each other, to thereby expand the diameter of the combined jaw elements within the end fitting. Each jaw element includes a plurality of rib segments projecting from an outer surface of the jaw element, the rib segments spaced along the length of the jaw element. The rib segments are defined by a radially outermost plateau, a fillet radius from the plateau to the outer surface of the jaw element.