Stahlwille series 10 double open ended spanner metric made from drop forged from high grade special chrome alloy steels and chrome plated manufactured to din 3110 iso 10102 the spanner has been optimally hardened in continuous furnaces with no scale build up or skin decarburisation and has been gentlly quenched in oil it is extremeley strong yet lightweight due to stahlwilles double t profile stahlwilles unique plating method prevents the problem of chrome flaking with 15 offset made in germany