Hollow bolt

The utility model discloses a hollow bolt, including head, screw rod, screw thread section and oil filler point, the screw rod comprises oiling curved surface and oiling platform, and the oiling curved surface is located the upper end of oiling platform, the side of oiling curved surface is equipped with the oil filler point, be equipped with surface -activeagent on the inner wall of oil filler point, the bottom connecting thread section of oiling platform. The utility model discloses simple structure, through oiling curved surface and the oiling platform structure that sets up separately on the screw rod, the relative speed that has made things convenient for the oil to get into the oil filler point, has improved work efficiency at the time of having practiced thrift. The phosphatide layer surface -activeagent who adds on the oil filler point inner wall simultaneously, the effectual surface tension who reduces the oil molecule for the oil molecule get into the oil filler point. 本实用新型公开了种空心螺栓，包括头部、螺杆、螺纹段和注油孔，