PartsTable
Technical Data Sheet
PartsTable / COMPONENT / MS21921-10D
MS21921-10D ✓ 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 2014 AND ALUMINUM ALLOY 2024 OVERALL, nut_style: TUBE COUPLING, nut_height: 0.990 INCHES MINIMUM AND 0.995 INCHES MAXIMUM IN, seat_angle: 45.00 DEGREES NOMINAL, thread_class: 3B, thread_series: UNIFIED NATIONAL JOINT FINE (UNJF). This part is cataloged in the Federal Logistics Information System (FLIS) under NSN 4730-00-555-8204, 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
MS21921-10D
NSN: 4730-00-555-8204
FSC: 4730
CAGE: 96906 — MILITARY STANDARDS PROMULGATED BY MILITARY DEPARTMENTS UNDER AUTHORITY OF DEFENSE STANDARDIZATION MANUAL 4120 3-M
SPECIFICATIONS
materialALUMINUM ALLOY 2014 AND ALUMINUM ALLOY 2024 OVERALL
nut_styleTUBE COUPLING
nut_height0.990 INCHES MINIMUM AND 0.995 INCHES MAXIMUM IN
seat_angle45.00 DEGREES NOMINAL
thread_class3B
thread_seriesUNIFIED NATIONAL JOINT FINE (UNJF)
thread_directionRIGHT-HAND
length_to_shoulder0.677 INCHES MINIMUM AND 0.697 INCHES MAXIMUM IN
width_across_flats0.996 INCHES MINIMUM AND 1.003 INCHES MAXIMUM IN
nominal_thread_size0.891 INCHES IN
smallest_inside_diameter0.690 INCHES MINIMUM AND 0.695 INCHES MAXIMUM IN
thread_quantity_per_inch14
NSN4730-00-555-8204
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: MS21921-10D · 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
•
THREAD DIRECTION: RIGHT-HAND
•
MATERIAL: ALUMINUM ALLOY OVERALL
•
SURFACE TREATMENT: ANODIZE OVERALL
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: MIL-A-8625,TY 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL
•
WIDTH ACROSS FLATS: 1.000 INCHES NOMINAL IN
•
NOMINAL TUBE OUTSIDE DIAMETER: 0.625 INCHES IN
•
THREAD SERIES: UNF
TECHNICAL CHARACTERISTICS (FLIS)
THREAD DIRECTIONRIGHT-HAND
MATERIALALUMINUM ALLOY OVERALL
SURFACE TREATMENTANODIZE OVERALL
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONMIL-A-8625,TY 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL
WIDTH ACROSS FLATS1.000 INCHES NOMINAL IN
END ITEM IDENTIFICATIONCH-47 HELICOPTER
NOMINAL TUBE OUTSIDE DIAMETER0.625 INCHES IN
THREAD SERIESUNF
NOMINAL THREAD SIZE0.875 INCHES IN
SMALLEST INSIDE DIAMETER0.690 INCHES MINIMUM AND 0.695 INCHES MAXIMUM IN
VERIFIED SUBSTITUTES & CROSS-REFERENCES 19
1569Interchangeable
interchangeable cross-reference
interchangeable
C5NN-7B155-AInterchangeable
interchangeable cross-reference
interchangeable
201569Interchangeable
interchangeable cross-reference
interchangeable
HP3400Interchangeable
interchangeable cross-reference
interchangeable
MS51800-5Interchangeable
interchangeable cross-reference
interchangeable
DWG5120-00-239-0035Interchangeable
interchangeable cross-reference
interchangeable
LIFECYCLE
StatusCANCELLED
Availability—
RoHS CompliantEAR99Not HAZMAT
Ready to buy MS21921-10D?
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 MS21921-10D?
MS21921-10D is a NUT,TUBE COUPLING.
What parts can replace MS21921-10D?
There are 19 known substitutes for MS21921-10D: 1569, C5NN-7B155-A, 201569 and 16 more. Substitute compatibility should be verified for your specific system.
Is MS21921-10D still available?
MS21921-10D is currently cancelled.
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 — MS21921-10D

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