Method for repairing cracks

A method for drawing opposite sides of a crack in a material toward each other while maintaining a ductility of the material, including the steps of:

• diagnosing an orientation of the crack with respect to a surface upon which the crack is exposed,
• forming a threaded cylindrical hole in the surface with a central axis of the hole co-planar with the crack orientation, the hole including threads having a hole major diameter and a hole minor diameter, with a top portion of each hole thread adjacent to the hole major diameter closer to the surface than any other portion thereof,
• providing a threaded pin having a threaded shaft with a diameter not greater than a diameter of the hole, a head and a shoulder above the threaded shaft and below the head, the shoulder having a diameter greater than the diameter of the hole, the pin including pin threads with a pin major diameter and a pin minor diameter with a top portion of each pin thread adjacent the pin major diameter closer to the head than any other part thereof, and
• threading the pin into the hole until the shoulder impacts the surface and the pin threads draw the hole threads on opposite sides of the crack toward each other.

A method for repairing a crack passing through a non-planar surface of a material, the steps including:

• forming a threaded cylindrical hole in the surface with a central axis of the hole co-planar with the crack orientation and with two opposite sides of the crack forming two sides of the hole, the hole including threads having a hole major diameter and a hole minor diameter, with the top portion of each hole thread adjacent to the hole major diameter closer to the surface than any other portion thereof,
• providing a threaded pin having a threaded shaft with a diameter not greater than a diameter of the hole, a head, and a shoulder below the head and above the threaded shaft, the shoulder having a diameter which tapers from a lesser diameter adjacent the threaded shaft similar to a diameter of the threaded shaft to a greater diameter portion above the lesser diameter portion, the greater diameter portion having a diameter greater than the diameter of the hole, the pin including pin threads with a pin major diameter and a pin minor diameter with a top portion of each pin thread adjacent the pin major diameter closer to the head than any other part thereof, and
• threading the pin into the hole until the shoulder is drawn below the surface and impacts sides of the hole, thus halting pin translation into the hole and causing the pin threads to draw the hole threads on the opposite sides of the hole together.