Although stainless steel has greater hardness, cobalt base alloys have higher wear resistance and a longer life. Cobalt is non-magnetic, so to determine whether you have a cobalt base alloy vs a stainless including cobalt, simply place a magnet over the blade. This cobalt 55BF is offset, has a 5 1/2" blade, weighs 36.5g and has a smaller size finger hole. The standard Joewell blade has a precision flat screw and a permanent finger rest.