Is it okay for the outward processing pen of Guangzhou Yichuang Industrial Co., Ltd. to have a little 502 mark?

Of course. 502 glue is a common glue, which is usually used to fix and bond articles. If there is a 502 mark on the pen, it may be because 502 glue was used during processing. If the function and quality of the pen are still good, the 502 mark may only be a surface defect and will not affect the use.