The stahlwille series 16 combination spanners are supplied in metric sizes and have a 15 offset ring end drop forged from high grade special steels with chrome plating manufactured to iso 3318 the spanners have been optimally hardened in continuous furnaces with no scale build up or skin decarburisation and have been gentlly quenched in oil they are extremeley strong yet lightweight due to stahlwilles double t profile stahlwilles unique plating method prevents the problem of chrome flaking the