Thread connection plug screw

The utility model discloses a thread connection plug screw, include: fixed cover, its first end with aerify connector thread and be connected, the plug screw body, it has seted up the centre bore, and the first end and the gas tube of plug screw body are connected, and the second end is in the second end of fixed cover stretches into fixed cover, and the counter bore has been seted up to the terminal surface of second end, the piston, it is installed in the counter bore to the axial displacement that can follow the counter bore. Under gas pressure's effect, thread connection plug screw's piston removes to the gas -charging connection direction of the part that awaits measuring to final supporting is leaned on on the terminal surface of gas -charging connection, and then the clearance between shutoff gas -charging connection and the fixed cover. The utility model discloses a thread connection plug screw need not artifical rotatory compressing tightly, and can both avoid owing to the wearing and tearing of rota