Abstract: In this paper, the authors summed up, analysed and made sure of some observations which they had taken part in and achieved from the technological experiments and research work of the crush-threading for one grade threaded hole-in 1622402 Diesel Engine 42CrMo connecting rod. Basing upon this consideration and by the foundation of scientific experiments the authors adopted high speed finish drilling with high pressure cooling forced chip-separation and single-point deep-hole drill for working of bottom threaded hole. Thus, the finish cut drilling process is instead of the procedures of drilling, enlarging and reaming at normal condition. Crush-threading one grade threaded hole provides ideal and necessary accurate bottom hole. In threading process they adopted crush-threading technology with a tap in special sestion. It is a new technology of ultitizing of metal cold plastic deformation characteristic under the action of external forces and the case of three phases strong stresses. Through one crush-threading thread accuracy achieves to 1 grade, and the finish mark of the thread face form is stably in ▽7, its tension strength increased 20-30%, shear strength increased 5-10 % , the depth of harding is 0.15mm, hardness increased more than 40%. This paper is also concerned with the preparing of one grade alloy steel bottom threaded hole and its basic principles, the technological method, the technological coefficient, and the designs and manufactures of tools and equipments used etc. There gives these problems a systematic explanation. Besides, the authors have mentioned their considerations of some technological problems-about this extent in the future development to be discussed.