Gasket material
Red Rubber (SBR) Gasket Material
Red rubber is styrene-butadiene rubber, often blended with natural rubber, sold as the low-cost general-purpose sheet for water, air and low-pressure flange gaskets. Its military callout is MIL-PRF-1149. We cut it to your drawing on the waterjet.
- Family
- SBR, or SBR and natural rubber blend
- Designations
- MIL-PRF-1149 (50 and 65 durometer)
- Product
- Sheet gaskets waterjet-cut to your drawing in Orange, California
Figures are the cited maker or standards values; the sheet datasheet and your application govern the final choice.
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.
What red rubber seals
Pump and pipe flanges on plumbing and irrigation lines, sump and tank covers, and general-purpose pads are its territory. It is a low-cost elastomer sheet, and that is the reason to choose it when the medium allows.
For oil, fuel or grease move to nitrile; for outdoor, steam or hot-water service, EPDM. Where bolted pipe joints need blowout resistance under bolt load, move to compressed non-asbestos fiber (CNAF). The same polymer as a molded seal is on the SBR O-ring page.
MIL-PRF-1149 on the print
MIL-PRF-1149 is the military performance specification for vulcanized synthetic rubber gasket materials of nominal 50 and 65 durometer hardness; revision E (2019) is current, validated by notice in 2024, and revision D dates from 1998 [S1]. The type and class digits pick the polymer and hardness; American Biltrite's Type I Class 2 sheet is a 50 A SBR at 1/8 in, 36 in wide [S2]. Put the full callout on the drawing and the sheet is sourced to it.
MIL-R-6855 (now MIL-PRF-6855) is a different document: the military specification for synthetic rubber sheet, strip and molded or extruded shapes, which lists styrene-butadiene for its Classes 3 and 5 [S3]. The MIL-R-6855 guide explains its classes and grades.
Specifications
Red Rubber (SBR) specifications
| Property | Value (in / mm, C / F as stated) | Source |
|---|---|---|
| Composition | SBR (American Biltrite MIL-PRF-1149 sheet) | [S2] |
| Durometer | 50 Shore A (MIL-PRF-1149 Type I Class 2 sheet) | [S2] |
| Tensile strength | 1000 psi minimum (MIL-PRF-1149 sheet) | [S2] |
| Designations | MIL-PRF-1149 (current revision E, 2019), Gasket Materials, Synthetic Rubber, 50 and 65 Durometer Hardness (Type I Class 2 in SBR) | [S1, S4] |
How we cut it
Gaskets are waterjet-cut to your drawing in Orange, California. Send a DXF, DWG or PDF with the thickness, the material or the specification callout, and the quantity. There is no die to build, so a single prototype and a repeat run go through the same setup, and a revision needs only a new file. The sheet comes from the sheet makers we buy from, to the callout on your print; the cutting is ours. Red rubber cuts cleanly on the waterjet, and the thickness your print names is confirmed on the quote.
Where Red Rubber (SBR) is used, and the usual alternatives
The print or the sheet datasheet governs; these are the sheets usually specified instead:
- Buna-N: when the medium is oil, fuel, grease or hydraulic fluid.
- EPDM: when the joint sees steam, hot water, sunlight or ozone.
- Neoprene: when moderate oil and weather resistance are both needed.
- Cork-rubber: when the cover is rough or warped and the bolt load is light.
Related gasket materials: Buna-N (Nitrile) Gasket Material, EPDM Gasket Material, Neoprene Gasket Material, Cork-Rubber Gasket Material, Butyl Rubber Gasket Material, Hypalon (CSM) Gasket Material. The full index is on the gaskets hub; send the drawing through request a quote.
Frequently asked
Is red rubber the same as SBR?
Red rubber is the trade name for SBR sheet, usually blended with natural rubber and colored red. Black SBR sheet is the same polymer.
What does MIL-PRF-1149 cover?
Vulcanized synthetic rubber gasket materials of nominal 50 and 65 durometer hardness. Revision E (2019) is current, so an older print may carry an earlier revision letter.
Which durometer should I choose?
MIL-PRF-1149 covers 50 and 65 durometer sheet, and the Type I Class 2 sheet cited here is 50 A. Softer conforms, harder holds shape; name the durometer on the print.
How thick can you cut it?
The thickness your print names is confirmed on the quote; the cited MIL-PRF-1149 Type I Class 2 sheet is 1/8 in.
Sources
- [S1] MIL-PRF-1149, Gasket Materials, Synthetic Rubber, 50 and 65 Durometer Hardness, DLA ASSIST document record (Active; revision D 1998, revision E 2019, E Notice 1 validation 2024), https://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=2849, accessed 2026-10-13.
- [S2] MIL-PRF-1149 type I, class 2 (SBR), American Biltrite, https://www.american-biltrite.com/rubber_us/mil-prf-1149-type-i-class-2/, accessed 2026-09-27.
- [S3] MIL-PRF-6855F with Amendment 1, Rubber, Synthetic, Sheets, Strips, Molded or Extruded Shapes, General Specification for, DLA ASSIST (the class list, paragraphs 1.2 and 6.1), https://quicksearch.dla.mil/qsDocDetails.aspx?ident_number=6165, accessed 2026-09-27.
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 Red Rubber (SBR) gasket drawing and the quantity
Upload a DXF, DWG or PDF of the gasket with the quote request, or a photo of the part with a ruler if no drawing exists. Add the sheet thickness, the durometer or grade, the quantity and whether adhesive backing is wanted. 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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