material:powder metallurgy Application:Dongfeng OEM No/Model:N/A Product Name:Internal Gear Ring The main material is powder metallurgy,and the process flows as follows: 1.pressing(the pressing machine is controled by computer to ensure the quality is stable and high precision) 2.Sinter 3.Sizing& Re-pressing 4.Finishing 5.After-treatment(Including oil dip,stream treatment and so on,in order to improving the surface hardness,cleanliness and the oiliness of the products) 6.Testing (air stream test,3D test,strength test,hardness test,run-out test)