In mandarin, "mechanical pencil lead"we called 自zi4 动dong4 笔bi3 铅qian1 芯xin1 but 笔bi3，we always omit it mechanical pencil 自zi4 动dong4 铅qian1 pencil lead 铅qian1 芯xin1

mechanical pencil lead in Chinese is 自动铅笔芯【自(zi,四声)动(dong,四声)铅(qian，一声)笔(bi，三声)芯(xin，一声)】