Military and Aerospace O-Ring Specifications (Freudenberg-First)
Use this chart to match common MIL, AMS, NAS, MS, and AS O-ring callouts to the correct base material family, typical temperature range, and a direct product path. If certification or traceability is required, contact us and we will quote to spec with the paperwork your quality team needs.
Tip: On mobile, each row becomes a stacked card for easier reading.
| Spec / Standard | Part or Sizing Series | Base Material | Typical Temp Range (°F) | Typical Use and Notes | Common Cross References | Buy |
|---|---|---|---|---|---|---|
AS568 (SAE Aerospace Size Standard) Geometry only | Dash sizes (AS568-XXX) | Any (depends on spec) | Varies by compound | Defines inside diameter and cross section tolerances only. Material and performance are controlled by the governing material spec. | Used as the base sizing for many NAS, MS, AS, and M-series callouts. | Shop AS568 O-Rings |
| AMS-P-25732 | MS28775 | NBR (Buna-N) | -65 to 275 | Legacy MIL-H-5606 hydraulic fluid applications. Often inactive for new designs, commonly replaced by AMS-P-83461. | Superseded size series: MS28784, MS28785. Older material references: MIL-P-25732, AN6227, AN6230. | AS568 Buna-N |
| AMS-P-83461 | M83461/1, M83461/2 | NBR (Buna-N) | -65 to 275 | Improved dynamic performance and longer service life versus MS28775. Used in MIL-H-5606 service. | Older reference: MIL-P-83461. | AS568 Buna-N |
| AMS-P-5315 | MS29512, MS29513 | NBR (Buna-N) | -65 to 158 | Aircraft fuel system sealing, including boss tube sizes where applicable. | Older reference: MIL-P-5315. | |
| AMS 7276 | AS3208, AS3209 | FKM (Viton type) | -13 to 400 | Aircraft fuels and lubricants. Common aerospace tube fitting sizing series. | Often associated with M83248/1, NAS1593, NAS1595, MS9387, MS9388 and related legacy callouts. | AS568 FKM 75 |
| AMS 7259 | AS3581 | FKM (High durometer) | -13 to 400 | High durometer FKM for fuels and lubricants where extrusion resistance is needed. | Often associated with M83248/2, MS9970 and related callouts. | |
| AMS 7287 | AS83485 | FKM GLT (Low temp) | -35 to 400 | Low temperature aerospace sealing where standard FKM gets too stiff. | Often associated with MIL-R-83485 and M83485/1. | |
| AMS 7257 | AS568 (dash sizes) | FFKM | +5 to 608 | Extreme chemical resistance and high temperature performance for aerospace and critical environments. | Simriz and other FFKM families depending on certification needs. | AS568 FFKM |
| NAS 1613 (Rev 5) | NAS1611, NAS1612 | Any (depends on spec) | -65 to 250 | Defines inside diameter and cross section tolerances only. Material and performance are controlled by the governing material spec. | Used as the base sizing for many NAS, MS, AS, and M-series callouts. | |
| AMS-R-25988 (Class and Grade) | M25988/1 to /4 | NBR (Buna-N) | -100 to 350 | Aircraft fuels and lubricants, excellent low-temp flexibility. Often blue by spec requirements depending on class/grade. | Superseded size series: MS28784, MS28785. Older material references: MIL-P-25732, AN6227, AN6230. |
Compliance note: This chart is intended to help customers translate common callouts to the correct material family and buying path. If you require QPL, CoC, traceability, batch test data, or a specific revision level, request a quote and include the full callout from the drawing.