M35 steel is high speed tool steel . It also is called SKH55 steel and 1.3243 steel. After the heat treatment, its hardness, red hardness and wear resistance can be improved.
It is a good material for making tools which can handle high impact and abrasion. And it always is used to make advanced die, screw dies, reamer, milling cutter, iron head, punch, complex shape tools with high toughness. It is easy to do the hot and cold process. After the quenching and tempering, the hardness will be the same as M42 steel . And the hardness of them is 66±1HRC and 67±1 HRC. M35 steel round bar plate sheet properties and chemical composition as below.