Never seen a finish like that. It looks like there was rust and someone may have used a die grinder and sanding disk around the circumference. Then some rough grit emery with an elongated twisting motion in an attempt to get rid of the swirls left by the grinder, followed by a heavy pass through a wire wheel on a bench grinder. Whether intentional for aesthetics or to remove some deep rust, there was some work put into it to get there, wouldn't call that a rough blank type of finish.