Timber Bolt Partially Threaded Galvanized

A round head bolt with a bearing surface that intersects with a shank at a 90° angle. Where the bearing surface and shank meet are four fins, 90° apart from each toher (it is an acceptable variation to have two fins 180° opposite each other). The underside of the head has a series of concentric circles. The shank is partially threaded with an unified thread pattern, and a blunt point