PartsTable
Technical Data Sheet
PartsTable / COMPONENT / AA557D6
AA557D6 ✓ Verified by PartsTable
— · HOSE FITTING
WHAT YOU NEED TO KNOW
PTFE tape on tapered threads (NPT/BSPT) JIC/AN flare connections seal metal-to-metal — no tape
NPT != BSPT — look identical, NOT interchangeable
PRODUCT OVERVIEW

The NUT,TUBE COUPLING is a the manufacturer industrial component. Key specifications include material: ALUMINUM ALLOY OVERALL, nut_style: TUBE COUPLING, nut_height: 0.729 INCHES NOMINAL IN, thread_class: 3B, thread_series: UNF, thread_direction: RIGHT-HAND. This product is currently in active production with full OEM support.

This part is cataloged in the Federal Logistics Information System (FLIS) under NSN 4730-00-908-6925, indicating validated use in U.S. government and defense logistics supply chains. Available through authorized enterprise resellers and TPM (Third Party Maintenance) channels.

Verify compatibility with your specific system configuration before ordering.

WHERE IT FITS
AA557D6
NSN: 4730-00-908-6925
FSC: 4730
CAGE: 06581 — ALLAN AIRCRAFT SUPPLY CO., LLC DBA ALLAN AIRCRAFT SUPPLY (USA)
SPECIFICATIONS
materialALUMINUM ALLOY OVERALL
nut_styleTUBE COUPLING
nut_height0.729 INCHES NOMINAL IN
thread_class3B
thread_seriesUNF
thread_directionRIGHT-HAND
surface_treatmentANODIZE OVERALL
length_to_shoulder0.603 INCHES NOMINAL IN
width_across_flats0.691 INCHES NOMINAL IN
nominal_thread_size0.562 INCHES IN
smallest_inside_diameter0.440 INCHES NOMINAL IN
thread_quantity_per_inch18
NSN4730-00-908-6925
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: AA557D6 · OEM ⚠ VERIFY BEFORE ORDERING NPT ≠ BSPT — tapered threads look identical but are NOT interchangeable. Wrong thread = leak. JIC (37°) ≠ AN (37°) ≠ SAE 45° — flare angles must match exactly. Measure thread pitch with gauge — visual identification is unreliable ✓ BROKER TIP Always use thread sealant (PTFE tape or pipe compound) on tapered threads (NPT/BSPT). JIC/AN flare fittings seal metal-to-metal — never use tape on flare connections PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
NUT STYLE: TUBE COUPLING
•
NOMINAL TUBE OUTSIDE DIAMETER: 0.375 INCHES IN
•
MATERIAL: ALUMINUM ALLOY OVERALL
•
SURFACE TREATMENT: ANODIZE OVERALL
•
LENGTH TO SHOULDER: 0.603 INCHES NOMINAL IN
•
WIDTH ACROSS FLATS: 0.691 INCHES NOMINAL IN
•
THREAD QUANTITY PER INCH: 18
•
SMALLEST INSIDE DIAMETER: 0.440 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS (FLIS)
NUT STYLETUBE COUPLING
NOMINAL TUBE OUTSIDE DIAMETER0.375 INCHES IN
MATERIALALUMINUM ALLOY OVERALL
SURFACE TREATMENTANODIZE OVERALL
LENGTH TO SHOULDER0.603 INCHES NOMINAL IN
WIDTH ACROSS FLATS0.691 INCHES NOMINAL IN
THREAD QUANTITY PER INCH18
SMALLEST INSIDE DIAMETER0.440 INCHES NOMINAL IN
NOMINAL THREAD SIZE0.562 INCHES IN
NUT HEIGHT0.729 INCHES NOMINAL IN
VERIFIED SUBSTITUTES & CROSS-REFERENCES 22
366Interchangeable
interchangeable cross-reference
interchangeable
30207Interchangeable
interchangeable cross-reference
interchangeable
FF-B-187AInterchangeable
interchangeable cross-reference
interchangeable
CALMInterchangeable
interchangeable cross-reference
interchangeable
H60MLQ30207Interchangeable
interchangeable cross-reference
interchangeable
3245Interchangeable
interchangeable cross-reference
interchangeable
LIFECYCLE
StatusACTIVE
AvailabilityOEM and secondary market
RoHS CompliantEAR99Not HAZMAT
Ready to buy AA557D6?
Compare prices from verified sellers on eBay
Buy on eBay →
As an eBay Partner, PartsTable may earn a commission. Your price is not affected.
FREQUENTLY ASKED QUESTIONS
What is AA557D6?
AA557D6 is a NUT,TUBE COUPLING.
What parts can replace AA557D6?
There are 22 known substitutes for AA557D6: 366, 30207, FF-B-187A and 19 more. Substitute compatibility should be verified for your specific system.
What is the NSN for AA557D6?
AA557D6 is cataloged in the Federal Logistics Information System (FLIS) under NSN 4730-00-908-6925. This indicates validated use in U.S. government and defense supply chains.
Community Feedback
Comments (0)
No comments yet. Be the first to share what you know.
Leave a Comment
Comments are reviewed before appearing. You will receive an email to verify before your comment appears.

Request a Quote — AA557D6

✓ Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com
Last verified: July 2026