It is not fastened to the machine on which it is used and may be moved around on the table of the drillingmachine to bring each bushing directly under the drill.
它不固定在使用它的钻床上，它能在钻床工作台上到处移动以使每个衬套都直接位于钻头下。
2
Drilling: refers to the use of drilling or milling machinedrill hole of the workpiece process.
钻孔：指在钻床或铣床上使用钻头对工件进行打孔的工艺过程。
3
The measures to control construction quality are analyzed, which are used to drill deep holes with normal circulation slewing drillingmachine.