A:

1. A special tool for tightening or loosening screws. It is composed of several inner hexagon type sleeves and one or several upper sleeve handles. The inner hexagon of the sleeve is arranged in order according to the bolt type and can be selected according to the need. The utility model relates to a water supply pipe connecting fitting, which can be used for connecting steel pipe with cast iron pipe, etc

2, steel connection sleeve, used for steel mechanical connection of a special product, divided into cold extrusion sleeve, cone thread sleeve and straight thread sleeve.

All the sleeves below are the same size as those of hex and dodecagon.