Mechanical lock cora with variable teath form

This invention is about a changeable mechanical lock chip, specifically a mechanical spring lockcore. On the lockcore and lockhead, it mainly adopts the working faces A,C with working springs and the working face B of switching springs, and the lockcore and lockhead have their own acceptance holes. In the acceptance holes of the lockcore are put back-moving and transitional springs and in those of the lockhead are back-moving and transitional flat heads. The switching steel balls are set between the working flat heads and the switching steel balls, switching between the working surfaces A,C and B. This structure is simple, compact and reasonable. The key can be used to change the lockcore and can switch and reset repeatedly and alternatively.