throughadv.通过；径直；自始至终；(电话)接通；完全prep.穿过；凭借；一直到adj.直达的；直通的；贯穿的；完成的；结束的through bias直通偏流

1. Its original heat treament processes were graphitizing annealing,quenching and tempering,then high-frequency hardening.
   同时因齿条形状特殊，高频淬火时易将齿部完全淬透，不能满足用户要求。