Enhanced tooling for interference-fit fasteners

A method comprising:

• selecting a die that applies force which plastically deforms a fastener in order to expand the fastener into interference with a hole;
• selecting a coating having a static coefficient of friction of less than 0.2;
• and
• permanently applying the coating to the die at a surface that will contact the fastener, thereby ensuring that plastic deforming of the fastener via force from the die will cause an amount of interference between the fastener and the hole along a length of the hole between one and a half thousandths of an inch and twenty thousandths of an inch.

A system comprising:

• multiple dies that secure a fastener at a hole, the dies comprising:
• a first die that contacts a first end of the fastener;
• and
• a second die that contacts a second end of the fastener,
• the second die includes a permanent coating having a static friction coefficient of less than 0.2 at a surface contacting the fastener;
• and
• the dies together apply force that plastically deforms the fastener, thereby expanding the fastener into interference with the hole along a length of the hole such that an amount of interference between the fastener and the hole along the length of the hole is greater than one and a half thousandths of an inch and less than twenty thousandths of an inch.

A method comprising:

• inserting a fastener into a hole;
• gripping the fastener via dies at ends of the fastener, at least one of the dies including a permanent coating having a static friction coefficient of less than 0.2 at a surface contacting the fastener;
• and
• plastically deforming the fastener via force from the dies, which results in columnar bulging that causes interference between the fastener and the hole along a length of the hole such that a ratio of a maximum amount of interference to a minimum amount of interference along the length of the hole is less than four.

An apparatus comprising:

• a first part;
• a second part;
• and
• a fastener placed within a hole that bridges the first part and the second part, the fastener securing the first part and second part together,
• the fastener has been plastically deformed, thereby expanding the fastener into interference with the hole along a length of the hole, such that a ratio of a maximum amount of interference to a minimum amount of interference along the length of the hole is less than four.

A method comprising:

• inserting a fastener into a hole;
• gripping ends of the fastener via dies;
• and
• plastically deforming the fastener into interference with the hole via force from the dies,
• a majority of plastic deformation at the fastener along an entire axial length of the fastener results in interference caused by columnar bulging of a shaft of the fastener in response to axial force from the dies such that an amount of interference between the fastener and the hole along the length of the hole is greater than one and a half thousandths of an inch and less than twenty thousandths of an inch.