Commercial Lighting,Led Troffers,Flat Panels,Vapor Tight Strips Fuonce-led , https://www.fuonce.com Our factory produces a small oil pump body (Fig. 1) with a hole diameter of φ9_0~(+0.02)mm, surface roughness R_40.4, roundness of 0.01, material ZL 107A. Due to the small aperture requirement, it is difficult to meet the drawing requirements. . First, the past processing method (1) φ9_0 ~ (+0.02) mm car to φ8.85_0 ~ (+0.058) mm, surface roughness R_43.2. (2) hinged with a standard reamer (six teeth)