To provide a metal member that can be used and fixed in any processes of press-in or insert molding the metal member into a resin product, and to provide a technique that can avoid production of burrs when the metal member is fixed in a press-in process.

A collar 10 has an outer diameter (first outer diameter d) on a side face end 14, which is equal to the inner diameter r of a through-hole 30; and has an outer diameter d' (second outer diameter d') of a knurled part 15, which is set to be slightly larger than the first outer diameter d. The depth t of the through-hole 30 of a resin product 20 is set to be slightly smaller than a height h of the collar 10. More specifically, protruding amounts of upper and lower annular circular surfaces of the collar are set to 0.3 mm respectively.