ān zhuāng / zuān tóu / qián / xiān / bǎ / qiǎ pán / nǐng jǐn / què rèn / zuān tóu / bú huì / sōng dòng

安装钻头前，先把卡盘拧紧，确认钻头不会松动。

Before installing the drill bit, tighten the chuck and make sure the bit will not come loose.