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MS21900-16K — NIPPLE,BOSS

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

MS21900-16K: NIPPLE,BOSS.

The NIPPLE,BOSS is a the manufacturer industrial component. Key specifications include material: STEEL COMP 316 OVERALL, thread_class: 3A ALL ENDS A, connection_type: THREADED EXTERNAL BOSS ALL ENDS, connection_style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END, style_designator: FLARED AND FLARELESS W/ CENTER WRENCHING FACILITY, nominal_thread_size: 1.312 INCHES ALL ENDS IN. This part is cataloged in the U.S.

Government catalog under NSN 4730-01-328-1816, 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
MS21900-16K
NSN: 4730-01-328-1816
FSC: 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
CAGE: 0U583 — SAE INTERNATIONAL DBA SAE INTERNATIONAL (USA)
SPECIFICATIONS
materialSTEEL COMP 316 OVERALL
thread_class3A ALL ENDS A
connection_typeTHREADED EXTERNAL BOSS ALL ENDS
connection_styleEXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END
style_designatorFLARED AND FLARELESS W/ CENTER WRENCHING FACILITY
nominal_thread_size1.312 INCHES ALL ENDS IN
nominal_overall_length1.969 INCHES IN
thread_quantity_per_inch12 ALL ENDS
thread_series_designatorUNIFIED NATIONAL JOINT (UNJ) ALL ENDS
specification/standard_data96906-MS21900 GOVERNMENT STANDARD
NSN4730-01-328-1816
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: MS21900-16K · 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
•
CONNECTION STYLE: FLARED W/ GASKET SEAL (BOSS) SECOND END
•
NOMINAL OVERALL LENGTH: 1.969 INCHES IN
•
CONNECTION TYPE: THREADED EXTERNAL BOSS ALL ENDS
•
STYLE DESIGNATOR: FLARED AND FLARELESS W/ CENTER WRENCHING FACILITY
•
NOMINAL THREAD SIZE: 1.312 INCHES ALL ENDS IN
•
SPECIFICATION/STANDARD DATA: 96906-MS21900 GOVERNMENT STANDARD
•
THREAD CLASS: 3A ALL ENDS A
TECHNICAL CHARACTERISTICS
CONNECTION STYLEFLARED W/ GASKET SEAL (BOSS) SECOND END
CONNECTION STYLEEXTERNAL SEAT FOR GASKET SEAL (BOSS) FIRST END
NOMINAL OVERALL LENGTH1.969 INCHES IN
CONNECTION TYPETHREADED EXTERNAL BOSS ALL ENDS
STYLE DESIGNATORFLARED AND FLARELESS W/ CENTER WRENCHING FACILITY
NOMINAL THREAD SIZE1.312 INCHES ALL ENDS IN
SPECIFICATION/STANDARD DATA96906-MS21900 GOVERNMENT STANDARD
THREAD CLASS3A ALL ENDS A
THREAD QUANTITY PER INCH12 ALL ENDS
MATERIALSTEEL COMP 316 OVERALL
OTHER ITEMS IN FSC 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
4730-00-000-1895 4730-00-000-4289 4730-00-000-4445 4730-00-000-8373 4730-00-000-8897 4730-00-001-0007 4730-00-001-0008
SUBSTITUTES & CROSS-REFERENCES 4
AS21900Reference document
Same NSN cross-reference
Reference document — Secondary reference
4730PL0802946Reference document
Same NSN cross-reference
Reference document — Informative reference only
SAE-AS18280Reference document
Same NSN cross-reference
Reference document — Design control — primary reference
137652143Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Normally procured from the manufacturer (OEM)No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is MS21900-16K?
MS21900-16K is a NIPPLE,BOSS.
What parts can replace MS21900-16K?
There are 4 known substitutes for MS21900-16K: AS21900, 4730PL0802946, SAE-AS18280 and 1 more. Substitute compatibility should be verified for your specific system.
What is the NSN for MS21900-16K?
MS21900-16K is cataloged in the U.S. Government catalog under NSN 4730-01-328-1816. This indicates validated use in U.S. government and defense supply chains.
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✓ PartsTable — the parts reference. Every fact cited to its source.
PartsTable Design LLC · partstable.com
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.
PartsTable commercial catalog: edition Unified commercial catalog snapshot through 2026-09-28, edition date not on file, retrieved 2026-09-28.