Vented hardware are specially designed fasteners that allow gases or fluids to freely pass thru them. These parts are typically used in vacuum and semiconductor applications. Vacuum hardware is typically electropolished and cleaned to meet strict cleanroom specifications.
THRU VENTED SCREWS
Vented Screws have a thru hole drilled in the centreline.
Vented screws are commonly available as socket cap screws, flat head screws, button head screws, hex cap screw,s and set screws
SLOT VENTED SCREWS
Slot Vented Screws have a channel machined through the threads of the screw and a portion of the head.
Slot Vents are typically more expensive than thru venting and the assembly requires more care to avoid cross-threading and galling.
VENTED WASHERS AND NUTS
Where a properly seated standard flat washer can seal air underneath the head of a screw a vented washer allows airflow in high vacuum thru the vent.
Same principle with vented nuts.