Full-Face and Ring Flange Gaskets
Full-face and ring flange gaskets, die cut or flash cut to ASME flange class callouts and held to ±0.003".
Cut from silicone (solid and sponge), Viton® / FKM, compressed non-asbestos fiber, neoprene, EPDM (solid and sponge), nitrile, cork-rubber, SBR (red rubber), PTFE and flexible graphite, to the pipe size, flange class and thickness on your order. Full-face gaskets are cut with the bolt holes.
Full-face gaskets, ring gaskets and non-standard flange gaskets to your drawing. Quick lead times.
- Full-face gaskets with bolt holes; ring gaskets inside the bolt circle
- Cut to ASME flange class callouts
- Die cut and flash cut gaskets to ±0.003"
- Flash cuts up to 60" × 120"
- Flash cutting from DXF or DWG, no die to buy
- Quotes within 1-2 business days
Flange gasket specifications
| Specification | Detail |
|---|---|
| Types | Full-face (with bolt holes) and ring (inside the bolt circle) |
| Flange callouts | Cut to ASME flange class callouts: pipe size and flange class |
| Non-standard flanges | Full-face and ring gaskets, including large diameters, to your drawing |
| Flash cutting | 60" × 120" table, up to 1.00" thick, no die, cut from DXF or DWG |
| Width | Up to 72" seamless (roll width) |
| Tolerance | Die cut and flash cut gaskets to ±0.003" |
| Thickness | To your order; the flash cutter takes up to 1.00" thick |
| Durometer | To your specification |
| Bolt holes | Cut with the gasket |
| Quantities | Single prototypes through production runs |
| Spiral wound gaskets | To ASME B16.20, quoted with flat flange gaskets (Spiral wound gaskets) |
Flange gasket materials
Cut from the material on your order. Silicone first, then by the volume we cut.
| Material | Forms | Notes |
|---|---|---|
| Silicone | Solid and sponge | Sheet and sponge gaskets; FDA-compliant grades |
| Viton® / FKM | Solid | Gaskets, washers and pads |
| Compressed non-asbestos fiber | Sheet | Flange gaskets and rings |
| Neoprene (CR) | Solid | Gaskets, washers and pads |
| EPDM | Solid and sponge | Gaskets, washers and pads |
| Nitrile (NBR) | Solid | Gaskets, washers and pads |
| Cork-rubber | Sheet | Gaskets |
| SBR (red rubber) | Solid | Gaskets, washers and pads |
| PTFE | Sheet | Gaskets |
| Flexible graphite | Sheet | Gaskets |
Related gasket pages, sheet and washers
The other gaskets we make, and the standard washers and silicone sheet in our catalog.
Other gaskets
Gaskets by type, the cutting process, and spiral wound gaskets for pipeline and flange service.
Silicone sheet and sponge
Solid, soft and high-strength silicone sheet; silicone sponge.
Specifications
Tolerance classes and material callouts.
Tooling and secondary operations
- Standard flange gaskets are quoted from the pipe size, flange class, type, material and thickness
- Flash cutting needs no die: prototypes and short runs are cut straight from your CAD file
- A die for repeat parts is a separate one-time line on the quote
- Bolt holes cut with the gasket
What we need to quote
- A drawing (PDF), or a CAD file: DXF or STEP
- A sample part, or a sketch with dimensions
- Material, durometer and color, or the specification your drawing calls out
- Quantities: each quote gives several quantity tiers
- Any documents you need with the parts: certificate of compliance, first article, test reports
- For a standard flange gasket: pipe size and ASME flange class, full-face or ring, material and thickness
- For a non-standard flange: outside and inside diameters, bolt circle, hole count and hole size
Add Flange Gaskets to your quote
Tell us about your project. It goes into your quote with any catalog parts you add, and you send it from the quote page.
Frequently asked questions
- What is the difference between a full-face and a ring flange gasket?
- A full-face gasket covers the whole flange face, out to the flange outside diameter, and has a hole for each bolt. A ring gasket sits inside the bolt circle and has no bolt holes. Full-face gaskets are also called full-faced gaskets.
- What do you need to quote a flange gasket?
- The pipe size and ASME flange class, full-face or ring, the material, the thickness and the quantity. For a non-standard flange, send a drawing or a DXF or DWG file. Quotes go out within 1-2 business days.
- Which materials do you cut flange gaskets from?
- Silicone, Viton® / FKM, compressed non-asbestos fiber, neoprene, EPDM, nitrile, cork-rubber, SBR (red rubber), PTFE and flexible graphite. Name the material or specification on your order.
- Which standard covers flange gasket dimensions?
- ASME B16.21 covers nonmetallic flat gaskets for pipe flanges: types, sizes, materials, dimensions, tolerances and markings. Name the pipe size and flange class on your order and the gasket is cut to that callout.
- How large a flange gasket can you cut?
- Flash cuts on a 60" × 120" table, and up to 72" wide in one piece. Large-diameter gaskets are quoted to your drawing.
- Do I need to buy a die?
- No die is needed for flash cutting, which cuts straight from your CAD file. A die for repeat parts is quoted as a separate one-time line.
- Do you also quote spiral wound gaskets?
- Yes. Spiral wound gaskets to ASME B16.20 are quoted with flat flange gaskets, so one quote can cover the gaskets for a flange set.
Typical parts by industry
Flange gaskets by industry, from our order records:
| Industry | Typical parts |
|---|---|
| Oil, gas and energy | Full-face and ring flange gaskets |
| Water and wastewater | Flange gaskets |
| Electrical and electronicsElectronics industry | Flange gaskets |
| Food, beverage and dairyFood & Dairy industry | Flange gaskets |
| Pharmaceutical and life sciencesHealthcare industry | Flange gaskets |
| Industrial machinery | Flange gaskets |
Full-face gaskets and ring gaskets
A full-face gasket covers the flange face out to the flange outside diameter and has a hole for each bolt.
A ring gasket, also called a flat ring gasket, sits inside the bolt circle, where the bolts center it. It has no bolt holes.
ASME B16.21 and flange class callouts
ASME B16.21 is the standard for nonmetallic flat gaskets for pipe flanges. It covers types, sizes, materials, dimensions, tolerances and markings, with gasket dimension tables for the ASME pipe flange standards.
How to specify a flange gasket
A complete flange gasket callout names:
- Pipe size and flange class, or the flange standard
- Full-face (with bolt holes) or ring (inside the bolt circle)
- For a non-standard flange: outside and inside diameters, bolt circle, hole count and hole size
- Material or specification, durometer and thickness
- Quantity per release and per year
Quality, documents and terms
Quality and documents
- ISO 9001:2015 certified quality system
- Certificates of compliance at no charge, on request
- First article inspection, test reports and PPAP-type documents on request where offered, quoted separately
Ordering terms
- Quotes within 1-2 business days, with several quantity tiers
- Quick lead times; the lead time is stated on every quote
- FOB Canonsburg, PA
- Tooling is quoted as a separate one-time charge
- Overruns and underruns per our quote terms
- Blanket orders with scheduled releases, with a release kept in stock for rush needs; blanket orders are non-cancellable
- Expedites quoted as an option
About National Rubber
National Rubber Corporation has supplied custom rubber parts from Canonsburg, Pennsylvania, since 1997. Mixing, extruding, molding, die cutting and splicing are done in house, and all design engineering and manufacturing is done in the USA.
Our quality system is ISO 9001:2015 certified. We work to your drawing and specification, and state the tolerance class, documents and terms on every quote. What we hold to: quality, integrity, customer focus and teamwork.
Request a quote
Send the pipe size, flange class, gasket type, material and thickness, or a drawing. Quotes go out within 1-2 business days.
Viton® is a registered trademark of The Chemours Company FC, LLC.