PartsTable
Technical Data Sheet
Download PDF

MS51531B20S — ADAPTER,STRAIGHT,TUBE TO BOSS

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

MS51531B20S: ADAPTER,STRAIGHT,TUBE TO BOSS.

The ADAPTER,STRAIGHT,TUBE TO BOSS is a the manufacturer industrial component. Key specifications include material: STEEL CORROSION RESISTING OVERALL, nut_style: TUBE COUPLING, nut_height: 1.230 INCHES NOMINAL IN, thread_class: 2B, thread_series: UN, thread_direction: RIGHT-HAND. This part is cataloged in the U.S.

Government catalog under NSN 4730-01-238-4032, 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
MS51531B20S
NSN: 4730-01-238-4032
FSC: 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
CAGE: 96906 — MILITARY STANDARDS PROMULGATED BY MILITARY DEPARTMENTS UNDER AUTHORITY OF DEFENSE STANDARDIZATION MANUAL 4120 3-M
SPECIFICATIONS
materialSTEEL CORROSION RESISTING OVERALL
nut_styleTUBE COUPLING
nut_height1.230 INCHES NOMINAL IN
thread_class2B
thread_seriesUN
thread_directionRIGHT-HAND
surface_treatmentPASSIVATE OVERALL
length_to_shoulder1.017 INCHES NOMINAL IN
width_across_flats2.000 INCHES NOMINAL IN
nominal_thread_size1.625 INCHES IN
smallest_inside_diameter1.344 INCHES NOMINAL IN
thread_quantity_per_inch12
NSN4730-01-238-4032
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: MS51531B20S · 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
•
LENGTH TO SHOULDER: 1.017 INCHES NOMINAL IN
•
WIDTH ACROSS FLATS: 2.000 INCHES NOMINAL IN
•
THREAD SERIES: UN
•
THREAD DIRECTION: RIGHT-HAND
•
NOMINAL THREAD SIZE: 1.625 INCHES IN
•
SPECIFICATION/STANDARD DATA: 96906 - MS51531 GOVERNMENT STANDARD AND 81349 - MIL-F-18866 GOVERNMENT STANDARD
•
NONDEFINITIVE SPEC/STD DATA: MS51531B20S REFERENCE NUMBER
•
NUT HEIGHT: 1.230 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
LENGTH TO SHOULDER1.017 INCHES NOMINAL IN
WIDTH ACROSS FLATS2.000 INCHES NOMINAL IN
THREAD SERIESUN
THREAD DIRECTIONRIGHT-HAND
NOMINAL THREAD SIZE1.625 INCHES IN
SPECIFICATION/STANDARD DATA96906 - MS51531 GOVERNMENT STANDARD AND 81349 - MIL-F-18866 GOVERNMENT STANDARD
NONDEFINITIVE SPEC/STD DATAMS51531B20S REFERENCE NUMBER
NUT HEIGHT1.230 INCHES NOMINAL IN
SURFACE TREATMENTPASSIVATE OVERALL
NUT STYLETUBE COUPLING
SUBSTITUTES & CROSS-REFERENCES 5
J514Reference document
Same NSN cross-reference
Reference document — Secondary reference
20-BTX-SSReference document
Same NSN cross-reference
Reference document — Secondary reference
20 070110SReference document
Same NSN cross-reference
Reference document — Secondary reference
MIL-DTL-18866Reference document
Same NSN cross-reference
Reference document — Identification reference
MIL-F-18866Reference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Insurance item — stocked against contingency demandNo demilitarization required
Ready to buy MS51531B20S?
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 MS51531B20S?
MS51531B20S is a ADAPTER,STRAIGHT,TUBE TO BOSS.
What parts can replace MS51531B20S?
There are 5 known substitutes for MS51531B20S: J514, 20-BTX-SS, 20 070110S and 2 more. Substitute compatibility should be verified for your specific system.
What is the NSN for MS51531B20S?
MS51531B20S is cataloged in the U.S. Government catalog under NSN 4730-01-238-4032. This indicates validated use in U.S. government and defense supply chains.
Community Feedback
Leave a Comment
Comments are reviewed before appearing. You will receive an email to verify before your comment appears.

Request a Quote — MS51531B20S

✓ 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.