Blind rivets and method for its manufacture

A blind rivet comprising:

• a mandrel shaft having a head disposed at one axial end:
• a hollow rivet shell having a cylindrical shape including an inner cylindrical surface and an outer cylindrical surface, said rivet shell surrounding said mandrel shaft, said outer cylindrical surface having at least one attenuation groove, said at least one attenuation groove including at least two recesses each having a surface that substantially forms a secant with respect to said outer cylindrical surface, said at least two recesses being disposed at substantially the same axial position, a predetermined angular area being disposed between adjacent recesses of said rivet shell, said predetermined angular area being in the shape of a hollow cylinder.

A blind rivet comprising:

• a mandrel shaft having a head disposed at one axial end;
• a hollow rivet shell having a cylindrical shape including an inner cylindrical surface and an outer cylindrical surface, said rivet shell surrounding said mandrel shaft, said outer cylindrical surface having at least one attenuation groove, said at least one attenuation groove including at least two recesses each having a surface that substantially forms a secant with respect to said outer cylindrical surface, said rivet shell being deformed radially inwardly in the area of said at least two recesses such that said radially inward deformation forms a projection that contacts said mandrel shaft.

A blind rivet comprising:

• a mandrel shaft having head disposed at one axial end;
• a hollow rivet shell having a cylindrical shape including an inner cylindrical surface and an outer cylindrical surface, said rivet shell surrounding said mandrel shaft, said outer cylindrical surface having at least one attenuation groove, said at least one attenuation groove including at least two recesses each having a surface that substantially forms a secant with respect to said outer cylindrical surface, wherein said mandrel shaft has an area of cross-sectional reduction.

A method of manufacturing a blind rivet comprising the steps of:

• placing a mandrel shaft having a head within a hollow rivet shell,
• producing at least one attenuation groove in an outer cylindrical surface of said rivet shell after said placing step such that at least two recesses are formed, each of said recesses having a bottom surface that substantially forms a secant with respect to said outer cylindrical surface.