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
- Temperature
- -23 C to 90 C (-10 F to 195 F), 65 A sheet; -34 C to 77 C (-30 F to 170 F), 75 A sheet, on the cited sheets
- Thickness
- 1/16 in to 1/4 in on the cited sheets; other gauges quoted
- Formats
- Rolls 36 in and 48 in wide
- Designations
- MIL-PRF-1149 (50 and 65 durometer); ASTM D2000 AA line callouts
- 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.
What red rubber seals
Red rubber is the sheet for water, air, anti-freeze, detergents and salt solutions at ordinary temperatures, with moderate oil and ozone resistance [S2]. 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.
Two published figures are shown because grades differ: a 65 A blend rated -23 C to 90 C and a 75 A sheet rated -34 C to 77 C [S2, S3]. For oil, fuel or grease move to nitrile; for outdoor, steam or hot-water service, EPDM.
MIL-PRF-1149 on the print
MIL-PRF-1149D covers vulcanized synthetic rubber gasket materials of nominal 50 and 65 durometer, and the older MIL-G-1149 name means the same document [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 [S4]. Put the full callout on the drawing and the sheet is sourced to it.
Specifications
Red Rubber (SBR) specifications
| Property | Value (in / mm, C / F as stated) | Source |
|---|---|---|
| Composition | Blend of styrene-butadiene rubber and natural rubber (Rubber-Cal 65 A sheet); SBR (American Biltrite MIL-PRF-1149 sheet) | [S2, S4] |
| Durometer | 65 plus or minus 5 Shore A (Rubber-Cal); 75 Shore A (Hennig); 50 Shore A (MIL-PRF-1149 Type I Class 2 sheet) | [S2, S3, S4] |
| Temperature, 65 A sheet | -23 C to 90 C (-10 F to 195 F) | [S2] |
| Temperature, 75 A sheet | -34 C to 77 C (-30 F to 170 F) | [S3] |
| Tensile strength | 435 psi minimum (65 A sheet); 600 psi (75 A sheet); 1000 psi minimum (MIL-PRF-1149 sheet) | [S2, S3, S4] |
| Thickness | 1/16, 1/8, 3/16 and 1/4 in on the cited sheets; other gauges quoted | [S2, S3] |
| Formats | Rolls 36 in and 48 in wide; sheet cut to size; adhesive backing available | [S2, S3] |
| Designations | MIL-PRF-1149D, 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. 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?
Synthetic rubber gasket materials of nominal 50 and 65 durometer hardness. MIL-G-1149 is the older name for the same specification.
Can red rubber take oil?
Only a little. Its oil and ozone resistance are moderate. Use nitrile for oil and fuel, and EPDM outdoors.
Which durometer should I choose?
65 A is the general-purpose sheet; 75 A resists extrusion under higher bolt load; the MIL-PRF-1149 Type I Class 2 sheet is 50 A. Softer conforms, harder holds shape.
How thick can you cut it?
The cited sheets run 1/16 in to 1/4 in, and other gauges are quoted. The waterjet cuts the full range.
Sources
- [S1] MIL-PRF-1149D, Performance Specification: Gasket Materials, Synthetic Rubber, 50 and 65 Durometer Hardness, EverySpec, http://everyspec.com/MIL-PRF/MIL-PRF-000100-09999/MIL-PRF-1149D_39451/, accessed 2026-09-13.
- [S2] SBR Red 65A sheet, Rubber-Cal, https://rubbercal.com/product/sbr-red-65a-1-16x36, accessed 2026-09-13.
- [S3] Red Rubber Gasket Material (SBR), Hennig Gasket & Seals, https://www.henniggasket.com/sbr-red-rubber, accessed 2026-09-13.
- [S4] 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 2026-09-13.
Related guides
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.
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