Swimming Pool Mosaic,Swimming Pool Mosaic Tile,Glass Mosaic For Swimming Pool Hundreds Flooring Co., Ltd , http://www.chglassmosaic.com The quick-change drill sleeve (Fig. 1) has high precision and is troublesome to manufacture. When the accuracy of the workpiece is not high, the drill sleeve with threaded structure (Fig. 2) can be used instead. It is connected to the drill template with a right-handed thread so that the drill sleeve and the drill template are tightened during the drilling process. The drill sleeve is characterized by low cost, easy replacement and reliable operation.