4-40 Phillips Flat Head Screws

4-40 Flat Head Screws (PFHS)

The use of 'Vented' fasteners inside a vacuum environment is critical. A non-vented, blind-threaded hole creates a gas pocket that's difficult or impossible to evacuate (pump down) without an escape path. A trapped gas will manifest it self as a 'virtual leak', which is difficult to locate and causes unwanted downtime. Accu-Glass 4-40 flat head screws are manufactured from vacuum compatible 18-8 grade stainless steel.