Fastener including a transition zone and method of use thereof
A fastener and a method of fastening are provided. The fastener can comprise a first end, an oppositely disposed second end, and an elongate portion intermediate the first end and the second end. The elongate portion comprises a first region adjacent to the first end and a second region adjacent to the second end. The first region extends a distance along the elongate portion and has a first diameter. The second region extends a distance along the elongate portion and has a second diameter different from the first diameter. The fastener comprises a transition zone which extends a distance along the elongate portion and connects the first region and the second region. The transition zone comprises a radiused region and a taper region.
1. A fastener comprising:
a first end;
an oppositely disposed second end; and
an elongate portion intermediate the first end and the second end and defining a longitudinal axis of the fastener, wherein the elongate portion comprises
a generally cylindrical first region adjacent to the first end, extending a distance along the elongate portion, and having a first diameter,
a generally cylindrical second region adjacent to the second end, extending a distance along the elongate portion, and having a second diameter different from the first diameter, and
a transition zone extending a distance along the elongate portion and connecting the first portion and the second portion, the transition zone comprising
a first radiused region comprising a shoulder defining a radius of curvature in a range of 0.0002 inch to 0.02 inch,
a second radiused region comprising a shoulder defining a radius of curvature in a range of 0.1 to 1 inch,
a first taper region comprising an angled surface defining an angle in a range of 2 degrees to 10 degrees relative to the longitudinal axis, and
a second taper region comprising an angled surface defining an angle in a range of 30 degrees to 70 degrees relative to the longitudinal axis, wherein the first radiused region is positioned intermediate the first taper region and the second taper region, and wherein the second radiused region is intermediate the first taper region and the first region.
2. The fastener of claim 1 , wherein the second diameter is less than the first diameter.
3. The fastener of claim 2 , wherein the first taper region extends a distance along the elongate portion in a range of 0.031 inch to 0.062 inch.
4. The fastener of claim 2 , wherein the first taper region is intermediate the first region and the first radiused region.
5. The fastener of claim 1 , wherein the first taper region comprises a shape of a portion of a cone.
6. The fastener of claim 1 , wherein the first taper region comprises an angled surface defining an angle in a range of 2 degrees to 7 degrees relative to the longitudinal axis.
7. The fastener of claim 1 , wherein the shoulder of the first radiused region defines a radius of curvature in a range of 0.001 inch to 0.009 inch.
8. The fastener of claim 1 , wherein the shoulder of the second radiused region defines a radius of curvature in a range of 0.1 to 0.8 inch.
9. The fastener of claim 8 , wherein the first taper region is intermediate the first radiused region and the second radiused region.
10. The fastener of claim 1 , wherein the fastener is selected from the group consisting of a threaded pin, a lockbolt, a bolt, and a blind fastener.
11. The fastener of claim 1 , wherein the second region comprises at least one of threads and a groove.
12. The fastener of claim 1 , wherein the second diameter is less than the first diameter, and wherein the fastener is adapted to be installed in a bore in a structure, the bore having a diameter greater than the second diameter.
13. The fastener of claim 12 , wherein the structure is an aircraft part.
14. The fastener of claim 1 , wherein the second region comprises at least one of internal threads and external threads.
15. A fastener comprising:
a first end;
an oppositely disposed second end; and
an elongate portion intermediate the first end and the second end and defining a longitudinal axis of the fastener, wherein the elongate portion comprises
a generally cylindrical first region adjacent to the first end, extending a distance along the elongate portion, and having a first diameter,
a generally cylindrical second region adjacent to the second end, extending a distance along the elongate portion, and having a second diameter less than the first diameter, the second region comprises threads and
a transition zone extending a distance along the elongate portion and connecting the first portion and the second portion, the transition zone comprising
a first radiused region comprising a shoulder defining a radius of curvature in a range of 0.0002 inch to 0.02 inch,
a second radiused region comprising a shoulder defining a radius of curvature in a range of 0.1 to 1 inch,
a first taper region comprising an angled surface defining an angle in a range of 2 degrees to 10 degrees relative to the longitudinal axis, wherein the taper region is intermediate the first region and the radiused region, and
a second taper region comprising an angled surface defining an angle in a range of 30 degrees to 70 degrees relative to the longitudinal axis, wherein the radiused region is positioned intermediate the first taper region and the second taper region, and wherein the second radiused region is positioned intermediate the first taper region and the first region.
16. A method for fastening, the method comprising:
inserting a second end of a fastener into a bore in a structure, the fastener including
a first end,
the second end disposed opposite the first end, and
an elongate portion intermediate the first end and the second end and defining a longitudinal axis of the fastener, wherein the elongate portion comprises
a generally cylindrical first region adjacent to the first end, extending a distance along the elongate portion, and having a first diameter,
a generally cylindrical second region adjacent to the second end, extending a distance along the elongate portion, and having a second diameter different from the first diameter, and
a transition zone extending a distance along the elongate portion and connecting the first region and the second region, the transition zone comprising
a first radiused region comprising a shoulder defining a radius of curvature in a range of 0.0002 inch to 0.02 inch,
a second radiused region comprising a shoulder defining a radius of curvature in a range of 0.1 to 1 inch,
a first taper region comprising an angled surface defining an angle in a range of 2 degrees to 10 degrees relative to the longitudinal axis, and
a second taper region comprising an angled surface defining an angle in a range of 30 degrees to 70 degrees relative to the longitudinal axis, wherein the radiused region is positioned intermediate the first taper region and the second taper region, and wherein the second radiused region is positioned intermediate the first taper region and the first region;
after inserting, forcibly contacting the bore with the transition zone of the fastener by at least one of pressing the fastener and pulling the fastener; and
securing the fastener within the bore by a friction fit between the first region of the fastener and the bore.
17. The method of claim 16 , further comprising inhibiting corrosion fatigue at a joint of the fastener and the structure.