hub flange meaning in English

桨毂安装盘
毂缘

Machine tools - mounting of plain grinding wheels by means of hub flanges
机床.采用轮毂法兰方式安装平面磨轮
Machine tools - mounting of plain grinding wheels by means of hub flanges iso 666 : 1996
机床.用轮毂式法兰安装平面磨轮
Hub flanges for double conical grinding wheels for portable grinding machines ; dimensions
轻便式砂轮机的双圆锥形磨砂轮的紧固毂缘.尺寸