Hollow screw
Hollow screw
Hollow screws, also known as vacuum screws, exhaust screws, and punch screws, are screws used in vacuum systems. The appearance of vacuum screws is almost the same as that of ordinary screws, except that there is a through hole in the central axis of the vacuum screw from beginning to end. In vacuum system equipment, one end of the screw hole is closed. When the screw is locked in, air will be "locked" between the tail end of the screw and the bottom end of the screw hole (threaded blind hole). If ordinary screws are used, when the system is vacuumed, these "locked" air will not be quickly drawn out due to the obstruction of the screws. Instead, it will be slowly discharged from the gap of the thread groove after vacuuming, affecting the vacuum system and even polluting it, making it impossible for the system vacuum to reach the target value. If vacuum screws are used, the gas in the blind hole will be quickly drawn out from the hole that runs through the center of the screw, allowing the system vacuum to reach the target value.
