The clamped inner cone surface is ground by a high-speed internal hole grinder and tested with a standard pneumatic measuring instrument. The tool holder thread is tested with a 4H grade thread ring gauge, the nut is tested with a 4H grade thread plug gauge, and the inner cone runout of the tool holder body is ≤0.005MM. ; The product is fully inspected for quality assurance, with a bright appearance, high hardness and long service life.