Swaged collar and swaged nut

A swaged collar for mounting by compression when inserted in a through hole in a resin part, the swage collar comprising:

• a sleeve of oval cross section including an axially lower thick-walled portion having a first wall thickness (t2), an axially upper thin-walled portion with a second wall thickness (t) thinner than the first thickness and an axial length (L) and defining a length (C) for the circumference at the center point of the inner and outer surfaces of the thin-walled portion, and a radial step axially between the thick-walled portion and the thin-walled portion;
• a flange formed on the thick-walled portion of the sleeve distal from the thick walled portion, with a flange diameter larger than the sleeve diameter;
• a through-hole with an oval cross section is partially defined by the sleeve and the flange;
• and
• wherein, for a Poisson ratio γ, the following relational expressions are satisfied:
• r
• =
• C
• /
• 2
• 
• π
• m
• =
• L
• π
• 4
• 
• r
• 2
• 
• t
• 2
• 12
• 
• (
• 1
• -
• γ
• 2
• )
• 1.2
• <
• m
• <
• 1.8
• and
• and the swage collar is compressable when the sleeve is inserted in a mounting hole in the resin part so that the thin-walled portion will buckle to form a buckled portion, and the resin part will be sandwiched between the flange and the buckled portion.