... surface treated by lapping finish . 3.The drive gears adopt high quality alloy steel , after heat treatment and lapping finish . 4 ... simultaneously .5,Pressure line shaft ,slotted wheel made of high quality alloy steel ,balancing the weight test ,the surface after ... plating 6,Selection of high quality alloy steel slotted knife ,tooth blade width of 7 mm. Die cutting part1,Youli cushion imported ...