right helicoid正: the first month of the lunar ...螺: spiral shell; snail; conch面: face螺面: spiral surface螺面角: angle of flanks of thread; angle of thread; thread angle下载手机词典可随时随地查词查翻译关注微信公众号：chachacidian，回复:正螺面，即可在微信中查询翻译
