This SAE Aerospace Standard (AS) covers scarf-cut polytetrafluoroethylene (PTFE) retainers (backup rings) for use in glands in accordance with AS4716. They are for use in hydraulic and pneumatic system components as anti-extrusion devices in conjunction with O-rings, packings and other elastomeric seals for static and dynamic applications. Because of the construction of groove dimensions, backup rings specific to rod applications are designated "R" Rod (Female), backup rings specific to piston applications are designated "P" - Piston (Male). Piston and rod types of virgin pigmented PTFE are also identified by color code which also distinguishes parts to this standard from those made from virgin PTFE to other standards. Backup rings specified herein have been designed for a temperature range of -65 to 275 °F (-54 to 135 °C) and a nominal operating pressure of 3000 psi (20.7 MPa) for code 09 material (AMS 3678/9). Alternate materials to AMS 3678 are offered for more arduous operating conditions. This specification includes material tests but does not include hydraulic or pneumatic performance tests.
SAE AS5781-2007 Referenced Document
SAE AMS3678-1999 Polytetrafluoroethylene (PTFE) Moldings and Extrusions Unfilled, Pigmented, and Filled Components
SAE AMS3678/1-1999 Type 1 Virgin Polytetrafluoroethylene (PTFE) Moldings and Extrusions
SAE AMS3678/10-2004 Type 10 Virgin Polytetrafluoroethylene (PTFE) Moldings or Extrusions with 15% Carbon Fiber
SAE AMS3678/2-1999 Type 2 15% Graphite Filled Virgin Polytetrafluoroethylene (PTFE) Moldings or Extrusions
SAE AMS3678/3-1999 Type 3 15% Glass, 5% Molybdenum Disulfide Filled Virgin Polytetrafluoroethylene (PTFE) Moldings or Extrusions
SAE AMS3678/4-1999 Type 4 25% Glass Filled Virgin Polytetrafluoroethylene (PTFE) Moldings or Extrusions
SAE AMS3678/5-1999 Type 5 Virgin Polytetrafluoroethylene (PTFE) Moldings or Extrusions with Pigment
SAE AMS3678/6-1999 Type 6 60% Bronze Filled Virgin Polytetrafluoroethylene (PTFE) Moldings or Extrusions
SAE AMS3678/7-2004 Type 7 Virgin Polytetrafluoroethylene (PTFE) Moldings or Extrusions with 25% Carbon and Graphite*， 2024-04-18 Update
SAE AMS3678/8-2004 Type 8 Virgin Polytetrafluoroethylene (PTFE) Moldings or Extrusions with 10% Carbon Fiber*， 2024-04-18 Update
SAE AMS3678/9-2004 Type 9 Virgin Polytetrafluoroethylene (PTFE) Moldings with Pigment for AS4716 Backup Rings
SAE AS4716-1993 Aerospace Standard, Gland Design, O-Ring and Other Elastomeric Seals
SAE AS5857-2005 Gland Design, O-ring and Other Elastomeric Seals, Static Applications
SAE AS5781-2007 history
2021SAE AS5781C-2021 Retainers (Backup Rings), Hydraulic and Pneumatic, Polytetrafluoroethylene Resin, Single Turn, Scarf-Cut, For Use in AS4716 Glands
2020SAE AS5781B-2020 Retainers (Backup Rings), Hydraulic and Pneumatic, Polytetrafluoroethylene Resin, Single Turn, Scarf-Cut, For Use in AS4716 Glands
2015SAE AS5781A-2015 Retainers (Backup Rings)@ Hydraulic and Pneumatic@ Polytetrafluoroethylene Resin@ Single Turn@ Scarf-Cut@ For Use in AS4716 Glands
2013SAE AS5781-2013 Retainers (Backup Rings), Hydraulic and Pneumatic, Polytetrafluoroethylene Resin, Single Turn, Scarf-Cut, For Use in AS4716 Glands
2007SAE AS5781-2007 Retainers (Backup Rings), Hydraulic and Pneumatic, Polytetrafluoroethylene Resin, Single Turn, Scarf-Cut, For Use in AS4716 Glands