Ball-point pen cap

摘要

A pen cap having at least two engaging portions (59f, 59r) specifically adapted to engage a receiving-side engaging portion (51f) formed on the mouthpiece-side end (7) of a hollow barrel and a receiving-side engaging portion (51r) formed on the tail-plug-side end of the hollow barrel (9), respectively. The engaging portions on the cap are at different locations along the cap's longitudinal axis. Furthermore, the engaging portions on the cap have their engaging surfaces disposed radially outward at different distances relative to the cap's longitudinal axis.