High strength bolts of 10.9 grade steel and with large width across flats makes use of the high bolt strength more efficiently than standard structural engineering bolts. Therefore either less high strength bolts of high strength bolts with a smaller diameter are required in connections. This leads to cost savings on all connections. On top of that, hexagonal bolt heads and nuts with large widths across flats keep the contact pressure under the washer low, so that the applied initial preload is maintained throughout the connections working life. PEINER high strength HS bolts are used in friction grip connections in end plate connections and in bearing type connections.