Machining method for threaded hole in outer circle

The invention relates to a method for machining a threaded hole in an outer circle, an outer ring positioning tool comprises a vertical plate and two positioning round pins, and the included angle between the two positioning round pins and the central point of the vertical plate is 120 degrees. The included angle between the connecting line between the positioning round pin at the upper end and the center point of the vertical plate and the vertical center line of the vertical plate is the same as the angle alpha between the mounting holes in the bearing outer ring closest to the threaded hole to be machined, and the vertical plate is mounted on the workbench. The outer ring positioning tool has the advantages that the outer ring positioning tool is designed, the outer ring of each bearing does not need to be marked, the pivotal bearing outer ring to be drilled and tapped can be quickly and accurately positioned and mounted, time is saved, positioning is accurate during drilling and tapping, and the machining