What is a Virtual Leak?
Vacuum systems often experience problems known as virtual leaks due to trapped volumes. A virtual leak is a source of gas that is released very slowly inside a vacuum system. A typical source of a virtual leak is a blind tapped hole within the vacuum system. Vented screws can be used to allow the trapped gas to rapidly escape.

How do Thread Vented Screws Help?
Signet thread vented screws are slotted along the threads and into the screw head. This slot along the threads allows the gas to be pumped rapidly from the bottom of the blind tapped hole and the screw threads which results in the avoidance of virtual leaks. The elimination of virtual leaks improves system performance. Signet thread vented screws provide the following benefits:

  • Elimination of Virtual Leaks
  • Retain More Mechanical Strength Compared to Other Venting Methods
  • Vents the Threads as well as the Bottom of the Blind Tapped Hole
  • Thread Venting may be the only way Longer Screws can be Vented

Signet thread vented screws are 18-8 series stainless steel and can be coated with parting agents to reduce galling or seizing. Coating options are molybdenum disulfide and tungsten disulfide. Signet thread vented screws can also be plated with silver. Thread vented screws can also be manufactured with other materials upon request.

The following thread vented screw types are available. Other head types are available upon request. A minimum quantity of 50 each per line item is required. There is more information about our Thread Vented Screws on our Product Data Sheet.


Head Type
Description Type Abbrev.
00-xxxx Milled Slot Across Threads to Vent
00-x0xx Socket Head Cap SHC
00-x1xx Phillips Flat Head PFH
00-x2xx Binding Head Slotted BHS
00-x3xx Hex Head HH
00-x4xx Socket Flat Head SkFH
00-x5xx Phillips Pan Head PPH
00-X6XX Cup Point SetCPS
00-x7xx Button Head BH
00-x8xx Slotted Pan Head SPH
00-x9xx Slotted Round Head SRH
00-xAxx Slotted Flat Head SFH
00-xBxx Flat Point SetFPS
  
 An OEM part number followed by "Ref" indicates a Signet improved design part. 
  
 
Signet products, Inc.
2 Davis Drive
Belmont, CA 94002
phone: (650) 592-3575
fax: (650) 592-7223
e-mail sales@signetproducts.com
  
   
   
      
 
Copyright Signet Products Inc. 2004 - 2006
Last update October 12, 2006