Gasket material
PTFE Gasket Material
PTFE gaskets in virgin, filled and expanded sheet for chemistry no elastomer survives: the forms we cut on the waterjet, the specifications that name them, and creep as the design issue.
- Family
- PTFE (virgin, filled and expanded sheet)
- Temperature range
- Set by the grade; the filled and expanded PTFE pages cite one sheet each
- Durometers
- not applicable (non-elastomer)
- Standards
- ASTM D3308, ASTM D3294; ASTM F104
- Product
- Sheet gaskets waterjet-cut to your drawing in Orange, California
Every common gasket sheet material is quick for us to source, and we cut it to your print on our waterjet. The other sheet materials are on the waterjet-cut gaskets page.
PTFE gaskets give near-universal chemical resistance in a non-elastic material: virgin, filled and expanded PTFE sheet resists nearly every medium a rubber gasket cannot, and the design problem moves from chemistry to creep and bolt-load retention. Each PTFE grade sheet (virgin, filled, expanded) states its own temperature range. Conquest cuts PTFE sheet gaskets on the waterjet, the correct process for a material that must never be laser-cut.
What we cut
Conquest cuts sheet gaskets on a pure-water waterjet, the one product made in house. Tolerance is set to your drawing and confirmed on the quote, and the waterjet's size limits are on the custom gaskets page. There is no die to build, so prototypes, revision changes and short runs go through the same setup as a repeat, and expensive stock nests tightly with no die-skeleton waste. We cut PTFE in three forms: virgin (skived) sheet at 1/32, 1/16, 1/8 and 1/4 in from 12 x 12, 24 x 24 and 36 x 36 in sheets, and filled (glass, mineral or barium-filled, GYLON®-type) and expanded (GORE®-type) sheet at 1/32 to 1/8 in from 30 x 30 and 60 x 60 in sheets. Molded and lathe-cut parts, and non-sheet compounds, are supplied from our manufacturers.
PTFE gasket specifications
| Property | Value | Source |
|---|---|---|
| Temperature range | Set by the grade; the filled and expanded PTFE pages cite one sheet each | The grade sheet |
| Specification callouts | ASTM D3308 (skived PTFE tape) and D3294 (molded PTFE sheet); ASTM F104 (nonmetallic gasket materials) | ASTM D3308-12(2022); ASTM D3294-15; ASTM F104, scope |
| Design issue | Creep under bolt load; filled and expanded grades reduce it | Garlock® GYLON brochure GSK 3:3 Rev K (filled grades); GORE GR Sheet Gasketing (expanded grades) |
Which PTFE, for which duty?
| Form | Strength | Weakness | Typical duty |
|---|---|---|---|
| Virgin (skived) PTFE | Purest; broadest chemical resistance; FDA-compliant grades common | Creeps most under load; loses bolt torque | Low-pressure chemical and food flanges, liners |
| Filled PTFE (GYLON-type) | Much better creep resistance; holds torque | Filler narrows chemical resistance slightly | Chemical-process flanges at pressure |
| Expanded PTFE (GORE-type) | Conforms to rough and warped faces; low bolt load | Compressible; needs stops on some joints | Glass-lined and fragile flanges, large diameters |
| PTFE-envelope over a rubber core | PTFE face with rubber resilience | Limited thickness; core material limits temperature | Raised-face flanges in mixed chemistry |
| PTFE backup rings (MS27595, MS28774) | Anti-extrusion for O-rings at pressure | Not a gasket | Hydraulic glands; see the groove design guide |
| UHMW and other plastics | Abrasion resistance | Lower temperature than PTFE | Wear pads, not gaskets |
Where PTFE is used, and the usual alternatives
It is usually specified where the medium defeats every elastomer (strong acids and bases, solvents, mixed chemistry), where nothing may leach into the product, or where a flange is fragile and needs the low seating stress of expanded PTFE. It is not the sheet where the joint needs elastic recovery or sees vibration and thermal cycling that unload the bolts; a rubber gasket (Viton®, EPDM) or a PTFE-envelope gasket keeps its seal there. The material is PTFE, whatever trade name the print uses.
Sources: ASTM D3308-12(2022), Standard Specification for PTFE Resin Skived Tape, https://store.astm.org/d3308-12r22.html, read 2026-10-13; ASTM D3294-15, Standard Specification for PTFE Resin Molded Sheet and Molded Basic Shapes, https://store.astm.org/d3294-15.html, read 2026-09-25; ASTM F104; MS27595; MS28774; Garlock, GYLON PTFE gasketing brochure GSK 3:3 Rev K, 'Resistance to cold flow (creep)' (legacy.garlock.com), for filled grades; W. L. Gore & Associates, GORE GR Sheet Gasketing, https://www.gore.com/products/gore-gr-sheet-gasketing ('without the creep and cold flow'), for expanded grades.
Garlock and GYLON are trademarks of Garlock Sealing Technologies; GORE is a trademark of W. L. Gore & Associates; Viton is a trademark of The Chemours Company. No affiliation or endorsement is implied.
Frequently asked
Why does a PTFE gasket leak after a few heat cycles?
Creep: the material flows under bolt load and the torque relaxes. Filled or expanded PTFE, or re-torquing after the first cycle, is the usual fix.
Is PTFE food safe?
Virgin PTFE grades are widely offered FDA compliant; the grade sheet, not the material name, is the evidence.
Can PTFE be laser-cut to save cost?
No. Laser cutting decomposes chlorinated and fluorinated polymers into toxic gases, so we cut them on the waterjet.
What is an ASTM F104 callout?
The ASTM classification system for nonmetallic gasket materials. Name the callout on the drawing and the quote matches a sheet to it.
Related guides
Setting Conquest Seal up as a supplier?
Orders are handled under Conquest Seal's AS9100D quality management system, whose certificate scope includes distribution.
Send the PTFE gasket drawing and the quantity
A DXF, DWG or PDF of the gasket, the sheet thickness, the PTFE form or grade and the quantity. Gaskets are cut in our own shop in Orange, California; a Conquest representative replies. Quotes answered within one business day. A person answers (714) 632-9830, Pacific business hours.
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