In this thesis, the new process will proposed which using diamond profile boring to boring 8-shaped hole in intermediate stainless steel plate of synthetic fiber gear pump. Academic analysis was made for gear pump’s flow rate, and analysis was made for the disadvantage of using brown alumina grinding wheel to grinding 8-shaped hole in intermediate plate’s internal surface. The critical technical of single crystal diamond’s material selecting, grinding, welding were solved, and diamond profile boring was designed and manufactured. We confirmed the boring parameters: “”, “” and “” through experiment and academic analysis. The qualified intermediate stainless steel plate with 8-shaped hole was using in one spinning factory; we conquered the grinding hole’s disadvantage and productivity is increasing 15 times.