Blind rivet nut, blind rivet nut arrangement and setting method

A blind rivet nut for insertion into an aperture formed in one or more layers of material comprising:

• a head forming a flange;
• a shank comprising a head end, a foot end and a cylindrical bore extending along a longitudinal axis from the head end to the foot end, the bore having a first bore segment near the foot end, provided with an internal thread and a second bore segment near the head end whose diameter is greater than the diameter of the first bore segment, the wall surrounding the second bore segment forming a deformable region of the shank and includes an external wall diameter, wherein the foot end includes a foot end diameter, the foot end of the shank including a tapered chamfer making a foot end angle of 21 to 25 degrees with the longitudinal axis, and wherein the ratio of the foot end diameter to the external wall diameter is between 0.65 and 0.82.