Timber Bolt Partially Threaded Galvanized

A round head bolt with a bearing surface that intersects with a shank at a 90?ø angle. Where the bearing surface and shank meet are four fins, 90?ø apart from each toher (it is an acceptable variation to have two fins 180?ø 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