1/4-20 x 3/8 in. Vacuum Vented Socket Head Cap Screws (SHCS), 1/4-20 Thread Size by 3/8 in. Long, 304 Stainless Steel, Sold as Each
1/4-20 x 3/8" Vacuum Vented Socket Head Cap Screws, 1/4-20 Thread Size by 3/8" Long, 304 Stainless Steel, Sold as Each.

These 1/4-20 x 3/8" long vacuum vented socket head cap screws (SHCS) are drilled through the head and shaft to vent fluid and gases trapped below the screw, making them necessary for vacuum applications. These vented scews are sold by the piece (1 each).

When used as vacuum fasteners inside a vacuum chamber, typical solid shaft (unvented) screws trap gases in the void space between the screw tip and the bottom of the threaded hole. These trapped gases are slowly released into the evacuated chamber thus creating what is known as a virtual leak. Virtual leaks slow down pumping processes and can significantly prolong the time needed to reach the desired base pressure. These vented screws, also known as vacuum screws, help eliminate virtual leaks from high vacuum (HV) and ultra-high (UHV) systems.

Our vacuum compatible vented screw fasteners have been drilled through the entire length of their shaft allowing these trapped gases to vent out. These screws are non-magnetic and made of chemical and corrosion resistant 304 stainless steel. The screw length is measured from under the head (length of shaft only).

We know that selecting the correct vacuum hardware for your vacuum system can seem like a challenging process. To make buying easier we sell the hardware individually by the bolt specifications (bolt diameter, thread type, and length), or in prepackaged hardware sets tailored for specific applications, such as for connecting ISO, CF (Conflat), or ASA flanges, or for connecting vacuum valves.

Links to bolt sets for some selected applications:


Please send us an email if you are looking to order large quantities of fasteners or other hardware. We can offer substantial discounts for bulk orders. If you cannot find the particular hardware you need, please send us an email and we will quote it for you: fasteners@idealvac.com

Product: 1/4-20 x 3/8 in. Vacuum Vented Socket Head Cap Screws (SHCS), 1/4-20 Thread Size by 3/8 in. Long, 304 Stainless Steel, Sold as Each
Condition:      New
Warranty:     Against Product Defect
Part Number: P108310
Price: $1.33