Turbofan engine on an airliner at the gate

Aerospace

Sealing parts for aerospace, to the specification on your print

If your print calls out a seal specification, we supply the part built to it and the paperwork that proves it. Conquest Seal is a distributor: the parts are made by manufacturers on the relevant qualified products list, where the document has one, and the certificate of conformance names the part number, the specification, the manufacturer, the lot and the quantity. Where a drawing still calls out a superseded document, we quote the current one, name both on the certificate, and confirm with you before ordering. Send the part number as it appears on the print and a Conquest representative replies with the quote.

Photo by Angel Sinigersky.

Standards
MIL-PRF-25732 (MS28775), AMS-P-83461, AMS7276 (AS3209), AMS7259 (AS3581), AMS-R-25988 (M25988), AMS7267, AMS7257
Typical seals
AS568 O-rings, MS28778 boss seals, fluorosilicone fuel-system O-rings, waterjet-cut sheet gaskets, molded and bonded parts to print
Materials
Nitrile, FKM, fluorosilicone, silicone, FFKM; the compound sheet sets the temperature limit
Quality
Certificate of conformance naming the part number, the specification, the manufacturer, the lot and the quantity; batch test reports where the program calls for them.

Aerospace buying is specification buying. The print names a document and a size, and the job is getting a part that was built to that document, from a source that is allowed to build it, with paperwork a quality department will accept. Most of the difficulty is in the third part.

What we supply against your print

Hydraulic and fuel-system O-rings, boss seals, and the fluorosilicone and fluorocarbon parts that fuel contact calls for. Flat gaskets are cut to your drawing on our own waterjet in Orange, California, from a DXF, with no tooling. Molded parts and rubber-to-metal bonded parts are made to your print by the molders we source from.

The mil-spec chart lists the documents and the sizes against them. The M83248 and AMS7276 guides decode the two callouts that come up most.

When the print names a cancelled document

It happens constantly, and it is not a problem. A drawing that still reads MIL-R-83248 refers to a document that was cancelled and replaced; we quote the current document, name both on the certificate and confirm with you before ordering, so the paperwork matches the drawing you are buying to. The register further down this page lists the documents we see most and what each one became.

If your drawing names something not on that list, send it anyway. Checking it beats guessing.

What ships with the part

A certificate of conformance naming the part number, the specification, the manufacturer, the lot and the quantity, and the manufacturer's batch test report where the program calls for one. Conquest Seal is not itself on a qualified products list, and no distributor is: the listing belongs to the manufacturer, and the certificate names it. Tell us at the quote stage if your receiving inspection needs anything beyond that.

Please don't send a drawing marked ITAR, EAR, CUI or export-controlled. For those parts, call (714) 632-9830.

Specification register

The document on the print and the document it became

A drawing that reads M83248/1 refers to a cancelled document; the part is supplied to its SAE successors, AS83248/1 with AMS7276, with both named on the certificate. Statuses were read from DLA ASSIST and SAE Mobilus on 2026-09-06.

DocumentPart familiesMaterialStatus
SAE-AS83248/1AS83248/1-xxx, M83248/1-xxx (legacy callout)FKMReaffirmed; current revision AS83248/1A (2021-11-08)
SAE-AMS7276AS3208-xxx, AS3209-xxx, AS83248/1-xxx, M83248/1-xxx (legacy)FKMActive
SAE-AMS7259AS3581-xxx, M83248/2-xxx (legacy)FKMActive
SAE-AMS7280AS3084-xxx, AS3085-xxxFKM (FPM)Revised; current revision AMS7280F (1992-01-01)
SAE-AMS-R-83485 (AMSR83485)M83485/1-xxxFKM (low temperature)current revision AMSR83485A (2014-05-28)
SAE-AMS-P-83461 (AMSP83461)M83461/1-xxxNBRIssued (1998-04-01)
SAE-AS83461/1AS83461/1-xxx, M83461/1-xxx (legacy callout)NBRcurrent revision AS83461/1C (2021-11-08)
MIL-P-25732 / MIL-PRF-25732MS28775-xxxNBRInactive
SAE-AMS-P-25732 (AMSP25732)MS28775-xxxNBRRevised; current revision AMSP25732A (2003-08-05)
SAE-AMS-P-5315 (AMSP5315)AS29512-xxx, AS29513-xxxNBRcurrent revision AMSP5315C (2022-08-05)
SAE-AMS7270AS3569-xxxNBRcurrent revision AMS7270M (2022-03-09)
SAE-AMS7271AS3578-xxxNBRRevised; current revision AMS7271K (2025-10-22)
SAE-AMS7272AS3551-xxxNBRcurrent revision AMS7272G (2013-04-12)
SAE-AMS7274AS3570-xxxNBRcurrent revision AMS7274K (2020-07-08)
MIL-DTL-25988 / MIL-R-25988M25988/1-xxx, M25988/2-xxx, M25988/3-xxx, M25988/4-xxxFVMQInactive
SAE-AMS-R-25988 (AMSR25988)M25988/1-xxx, M25988/2-xxx, M25988/3-xxx, M25988/4-xxxFVMQRevised; current revision AMSR25988B (2023-06-27)
SAE-AMS3325M25988/3-xxx (legacy cross-reference)FVMQcurrent revision AMS3325H (2024-09-11)
SAE-AMS3304AS3582-xxxVMQcurrent revision AMS3304J (2019-04-05)
SAE-AMS7267AS9386-xxx, AS9385-9yyVMQcurrent revision AMS7267H (2021-05-19)
SAE-AS28775AS28775-xxx, MS28775-xxx (legacy callout)NBRcurrent revision AS28775A (2025-02-08)
SAE-AS28778AS28778-yy, MS28778-yy (legacy callout)NBR (boss gasket; usually supplied at 90)current revision AS28778C (2021-11-08)
SAE-AS29513AS29513-xxx, MS29513-xxx (legacy callout)NBRcurrent revision AS29513C (2021-11-09)
SAE-AS29512AS29512-xxx, MS29512-xxx (legacy callout)NBRcurrent revision AS29512C (2021-11-09)
SAE-AS9385AS9385-9yy, MS9385-9yy (legacy callout)VMQ (AMS7267)Reaffirmed; current revision AS9385A (2020-10-26)
SAE-AS9386AS9386-xxx, MS9386-xxx (legacy callout)VMQ (AMS7267)Reaffirmed; current revision AS9386B (2021-07-07)
SAE-AS3084AS3084-xxxFKM (via AMS7280)Reaffirmed/current; AS3084A (2012-06-06)
SAE-AS3085AS3085-xxxFKM (via AMS7280)Reaffirmed/current; AS3085A (2012-06-06)
SAE-AS3208AS3208-xxxFKM (via AMS7276)Reaffirmed/current; AS3208A (2020-05-12)
SAE-AS3209AS3209-xxxFKM (via AMS7276)Reaffirmed/current; AS3209C (2021-08-03)
SAE-AS3551AS3551-xxxNBR (via AMS7272)Reaffirmed/current; AS3551A (2020-10-09)
SAE-AS3569AS3569-xxxNBR (via AMS7270)Reaffirmed/current; AS3569A (2021-08-09)
SAE-AS3570AS3570-xxxNBR (via AMS7274)Reaffirmed/current; AS3570A (2025-07-17)
SAE-AS3578AS3578-xxxNBR (via AMS7271)Reaffirmed/current; AS3578 (2018-08-23)
SAE-AS3581AS3581-xxxFKM (via AMS7259)Reaffirmed/current; AS3581A (2020-05-12)
SAE-AS3582AS3582-xxxVMQ (via AMS3304)Reaffirmed/current; AS3582 (2018-08-23)
SAE-AS568AS568-xxx dash numbersn/a (dimensional standard)current revision AS568F (2026-01-29)
SAE-AS8791MS28774-xxx, MS28782-xx, MS27595-xxxPTFE (back-up ring)current revision AS8791D (2025-07-16)
MIL-DTL-25988/1M25988/1-xxxFVMQ (fluorosilicone)Active; Revision B Notice 1 (Validation), 21-APR-2026
MIL-DTL-25988/2M25988/2-xxxFVMQ (fluorosilicone)Active; Revision A Notice 1 (Validation), 21-APR-2026
MIL-DTL-25988/3M25988/3-xxxFVMQ (fluorosilicone)Active; Revision A Notice 1 (Validation), 21-APR-2026
MIL-DTL-25988/4M25988/4-xxxFVMQ (fluorosilicone)Active; Revision A Notice 1 (Validation), 21-APR-2026; next review 20-APR-2031

Materials

What comes up on aerospace prints

VitonĀ® (FKM) O-Rings
Fuel, engine oil and heat. The most common aerospace callout after nitrile.
Silicone O-Rings
Static seals and wide temperature swings, where the part is not in fuel.
Buna-N O-Rings
Hydraulic systems and general service. The workhorse.
FFKM O-Rings
Where nothing else survives the chemistry or the heat. Specify the grade, not the family.

The compound named on your print governs. Send it with the part number and we quote that compound.

Viton is a trademark of The Chemours Company. No affiliation or endorsement is implied.

What to send us

The part number as it appears on the print, and the quantity. If the program needs a first article report or a batch test report, say so with the request. A Conquest representative replies with the quote and tells you what the order will ship with.

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