Mil-spec part number, M83248/1 and M83248/2 family

M83248/1-345 O-ring: fluorocarbon (FKM), the AS568-345 size

M83248/1-345 is the AS568-345 O-ring size, 3.975 in (100.97 mm) inside diameter by 0.210 in (5.33 mm) cross-section, in fluorocarbon (FKM) procured to MIL-R-83248/1 (Class 1) (the DLA ASSIST title names Class 1). The DLA ASSIST and SAE Mobilus records read: Canceled (MIL-R-83248/1); AS3209C stabilized (2021); AS83248/1A current (revised 2016, reaffirmed 2021). The dash sets the size and the document sets the compound, so an AS568-345 in another compound is not the same part as M83248/1-345. Send the designator exactly as the print reads and we quote it against that document.

Inside diameter: 3.975 in100.97 mm, +/- 0.028 in
Cross-section: 0.210 in5.33 mm, +/- 0.005 in
AS568 size: AS568-3453xx series
Document status: CanceledMIL-R-83248/1

Request a quote for M83248/1-345 M83248/1 and M83248/2 family AS568-345 size page

Dimensioned from the AS568 table for AS568-345, the size M83248/1-345 names. Not to scale.

Part facts

M83248/1-345: document, status, polymer and size
Item	Value
Part number	M83248/1-345
NSN	5331-00-184-3472 (DLA FLIS, read 2026-10-08)
Procured to	MIL-R-83248/1 (Class 1) (Class 1 in the DLA ASSIST title)
SAE document	SAE AS3209, to which DoD's 2008 cancellation notice pointed future purchases (the boss sizes, M83248/1-901 to -932, to SAE AS3208); its material specification is SAE AMS7276. SAE later issued SAE AS83248/1, O-ring molded from AMS7276 material, in December 2014 (AS83248/1A current, reaffirmed November 2021), and DoD adopted it on 2025-11-03
Status	Canceled (MIL-R-83248/1); AS3209C stabilized (2021); AS83248/1A current (revised 2016, reaffirmed 2021)
Base polymer	Fluorocarbon (FKM)
AS568 size	AS568-345
CAD for the AS568-345 size	AS568-345 STEP 3D solid, AS568-345 DXF 2D drawing, AS568-345 PDF dimensioned drawing; generated from the AS568 nominal dimensions, so verify against your drawing
Back-up rings	MS28774-345 (single-turn scarf-cut PTFE) or MS27595-345 (continuous PTFE), both procured to SAE AS8791; both drawings are inactive for new design

M83248/1-345: dimensions and tolerances from the AS568 table
Dimension	Value	Tolerance
Inside diameter (ID)	3.975 in 100.97 mm	+/- 0.028 in (0.71 mm)
Cross-section (W)	0.210 in 5.33 mm	+/- 0.005 in (0.13 mm)
Outside diameter (reference)	4.395 in 111.63 mm	derived: ID + 2 x W

Millimeter values are converted from the inch table. DoD cancelled MIL-R-83248/1, the slash sheet behind the M83248/1 part numbers, on 2008-07-24 and pointed future purchases to SAE AS3209, with the boss sizes (M83248/1-901 to -932) to SAE AS3208; SAE later issued AS83248/1, O-ring molded from AMS7276 material, in December 2014, and DoD adopted it on 2025-11-03 (DLA ASSIST: MIL-R-83248/1A Notice 5, read 2026-09-29, and ident 286630, read 2026-09-25; SAE Mobilus AS83248/1A, read 2026-09-27).

Same nominal size, other documents

Other part numbers for the AS568-345 size

These part numbers name the AS568-345 nominal size under a different document, so each one is a different compound. They are not interchangeable with M83248/1-345 unless the print or the buyer's engineering allows it. At this size the family sheets for MS28775-345, MS29513-345 and AS9386-345 hold a tighter inside-diameter tolerance than AS568.

Part standards that call out the AS568-345 nominal size
Part number	Document	Polymer	Status
MS28775-345	MIL-PRF-25732 (MS28775 part drawing)	NBR	Inactive (MIL-PRF-25732); AS28775A current
M83461/1-345	MIL-P-83461/1	NBR	Canceled; AS83461/1C current
M83248/2-345	MIL-R-83248/2 (Class 2)	FKM	Canceled; AS3581A stabilized; AS83248/2A current
AS3209-345	SAE AS3209 (AMS7276)	FKM	AS3209C stabilized
M83485/1-345	MIL-R-83485	FKM, low-temperature grade	Canceled
M25988/1-345	MIL-DTL-25988/1	FVMQ	Active
M25988/2-345	MIL-DTL-25988/2	FVMQ	Active
M25988/3-345	MIL-DTL-25988/3	FVMQ	Active
M25988/4-345	MIL-DTL-25988/4	FVMQ	Active
MS29513-345	MIL-P-5315 (MS29513 part drawing)	NBR	Canceled (MIL-P-5315); AS29513C current
AS3582-345	SAE AS3582 (AMS3304)	VMQ silicone	AS3582 current
AS9386-345	SAE AS9386 (AMS7267)	VMQ silicone	AS9386B current

The base polymer

M83248/1-345 is fluorocarbon (FKM). The Parker® O-Ring Handbook ORD 5700 range published for the FKM family (section 2.2) is -26 C to 204 C. That is the polymer family's range, not this document's requirement; the compound sheet for the qualified grade governs.

Material page: Fluorocarbon (FKM) O-rings. Every document in the family: M83248/1 and M83248/2 O-rings.

Nearby M83248/1 part numbers

Part number	ID in	ID mm	W in	W mm
M83248/1-330	2.100	53.34	0.210	5.33
M83248/1-333	2.475	62.87	0.210	5.33
M83248/1-342	3.600	91.44	0.210	5.33
M83248/1-345	3.975	100.97	0.210	5.33
M83248/1-352	4.850	123.19	0.210	5.33
M83248/1-353	4.975	126.37	0.210	5.33
M83248/1-358	5.600	142.24	0.210	5.33

Frequently asked

What is the AS568 equivalent of M83248/1-345?

M83248/1-345 is the AS568-345 size: 3.975 in (100.97 mm) inside diameter by 0.210 in (5.33 mm) cross-section. The dash sets the size; MIL-R-83248/1 (Class 1) sets the fluorocarbon (FKM) compound. An AS568-345 ring in any other compound has the same dimensions but is not the same part as M83248/1-345.

What is the NSN for M83248/1-345?

DLA's public FLIS data lists M83248/1-345 on NSN 5331-00-184-3472 (read 2026-10-08). An NSN is the federal catalog's number for the item; your contract or print decides what is ordered.

Is MIL-R-83248/1 still active?

The document status reads: Canceled (MIL-R-83248/1); AS3209C stabilized (2021); AS83248/1A current (revised 2016, reaffirmed 2021). It comes from the DLA ASSIST and SAE Mobilus records listed under Sources, with the date each was read. DoD cancelled MIL-R-83248/1 on 2008-07-24 with Notice 5, which pointed future purchases of the M83248/1 O-rings to SAE AS3209 and of the boss sizes, M83248/1-901 to -932, to SAE AS3208, and cautions users to evaluate a replacement for their own application; AS3209's current revision, AS3209C, was stabilized in August 2021. SAE later issued AS83248/1, O-ring molded from AMS7276 material, in December 2014; its current revision, AS83248/1A (revised October 2016, reaffirmed November 2021), was adopted by DoD on 2025-11-03 and is Active in DLA ASSIST. A canceled or inactive MIL document can still be the one a print calls out, and your print decides which you order to.

How do I order M83248/1-345?

Send the designator exactly as the print reads, with its revision, any suffix letter, the quantity and the paperwork the order needs. M83248/1-345 is quoted and supplied against MIL-R-83248/1 (Class 1), or, where the print allows it, SAE AS3209 or SAE AS83248/1, both on SAE AMS7276 material, in the compound the print calls out, with a certificate of conformance with every order. When the print calls out a QPL-listed specification, the finished molded O-ring, or the material it is molded from, comes from a manufacturer listed on that QPL; Conquest supplies it and is not itself on any QPL. A Conquest representative replies within one business day.

Sources

DLA ASSIST document details, idents 33574 and 33575 (MIL-R-83248 slash sheets), 105727 (AMS7276) and 105726 (AMS7259), read 2026-09-24; idents 33573 (MIL-R-83248), 18175 (MIL-R-25897), 286630 (SAE-AS83248/1) and 286631 (SAE-AS83248/2), read 2026-09-25; the MIL-R-83248/1A cancellation notice (Notice 5, 2008-07-24), read 2026-09-29; SAE Mobilus: AMSR83248A (2005-09-22), read 2026-09-24; AMS7276J (2020-05-18), read 2026-09-25; AS83248/1A (revised October 2016, reaffirmed 2021-11-08), AS3209C (stabilized 2021-08-03), AS3581A (stabilized 2020-05-12) and AS3208A (stabilized 2020-05-12), read 2026-09-27; the NSNs from DLA's public FLIS data (PUB LOG Reference, Identification and Characteristics files, updated 2026-10-01, read 2026-10-08); an NSN is the federal catalog's stock number for an item and does not name or approve a supplier; AS568 dimensions from the Parker O-Ring Handbook ORD 5700, 2021 printing, section IX, AS568 size tables (Series 2-XXX and 3-XXX), pages 9-2 to 9-11, read 2026-10-13; the dash-to-size mapping from the Freudenberg Sealing Technologies, Aerospace Part and Material Cross-Reference brochure (July 2024), pages 3 and 4, read 2026-10-13; the other part numbers' dash-to-size mapping and tolerance note from the MS28775 Revision E sheet (1984-03-23, read 2026-10-04), MS29513 Revision C sheet (1966-09-16, read 2026-09-27) and MS9386 Revision B sheet (1975-01-17, read 2026-09-27), DLA ASSIST; the other part numbers' statuses from DLA ASSIST document details, idents 18115 (MIL-PRF-25732), 33814 (MIL-P-83461/1), 33575 (MIL-R-83248/2), 33840 (MIL-R-83485/1), 18214 (MIL-DTL-25988/1), 18215 (MIL-DTL-25988/2), 18216 (MIL-DTL-25988/3), 18217 (MIL-DTL-25988/4) and 5334 (MIL-P-5315), read 2026-09-24; SAE Mobilus current-revision records AS83248/2A, read 2026-09-28; AS83461/1C, AS3581A, AS3209C, AS29513C, AS3582 and AS9386B, read 2026-09-27; AS28775A, read 2026-09-25; the SAE-AS83248/2 adoption record, DLA ASSIST ident 286631, read 2026-09-28; the polymers from the Parker O-Ring Handbook ORD 5700A/US, section 8, pages 8-2, 8-4 and 8-5 (read 2026-09-24); the back-up ring pairing and cut styles from the same handbook, section 6, pages 6-8 and 6-9 (read 2026-09-25); SAE AS8791 and the drawings' status from the MS28774M and MS27595E drawings, DLA ASSIST (read 2026-09-28); Parker O-Ring Handbook ORD 5700A/US, section 2.2, for the polymer family range (read 2026-09-14). Facts are stated in our own words and arrangement; no standard's text or table is reproduced.

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Last updated October 13, 2026