1.  Smelting  Method: EAF+LF+VD                                           

normal style="MARGIN-LEFT: 52.5pt; TEXT-INDENT: -52.5pt; mso-char-indent-count: -5.0">2．Forging: The forging ratio shall be not less than 3.0. The shape of forgings shall be according to the requirement of the drawing (rough turned forgings).       

3.  Heat treatment: Quenching & Tempering                                                                 

4.  Machining:  

According to the drawing, the externality and dimensions must meet the requirement of the drawing. External surface area: Ra 3.2; Internal surface: Ra 6.3—12.5