PartsTable
Technical Data Sheet
Download PDF

MS51811-27 — ADAPTER,STRAIGHT,TUBE TO BOSS

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

MS51811-27: ADAPTER,STRAIGHT,TUBE TO BOSS.

The ADAPTER,STRAIGHT,TUBE TO BOSS is a the manufacturer industrial component. Key specifications include material: STEEL COMP 12L14 OVERALL, leg_length: 1.890 INCHES NOMINAL ALL ENDS IN, seat_angle: 12.0 DEGREES ALL ENDS, thread_class: 2A ALL ENDS A, connection_type: THREADED EXTERNAL TUBE ALL ENDS, connection_style: FLARELESS (TUBE) ALL ENDS. This part is cataloged in the U.S.

Government catalog under NSN 4730-01-006-9931, 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
MS51811-27
NSN: 4730-01-006-9931
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 COMP 12L14 OVERALL
leg_length1.890 INCHES NOMINAL ALL ENDS IN
seat_angle12.0 DEGREES ALL ENDS
thread_class2A ALL ENDS A
connection_typeTHREADED EXTERNAL TUBE ALL ENDS
connection_styleFLARELESS (TUBE) ALL ENDS
operating_pressure3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
nominal_thread_size1.625 INCHES ALL ENDS IN
maximum_operating_temp250.0 FAHRENHEIT SINGLE RESPONSE DEGF
media_for_which_designedHYDRAULIC FLUID SINGLE RESPONSE
thread_quantity_per_inch12 ALL ENDS
thread_series_designatorUN ALL ENDS
NSN4730-01-006-9931
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: MS51811-27 · 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
•
FURNISHED ITEMS AND QUANTITY: 3 TUBE COUPLING NUT W/SLEEVE
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: J514 ASSN STD SINGLE TREATMENT RESPONSE AND MIL-C-81562, TY 1, CL 3 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL
•
CONNECTION STYLE: FLARELESS (TUBE) ALL ENDS
•
CONNECTION TYPE: THREADED EXTERNAL TUBE ALL ENDS
•
MATERIAL DOCUMENT AND CLASSIFICATION: 66 FED STD SINGLE MATERIAL RESPONSE OVERALL
•
NOMINAL OUTSIDE DIAMETER TUBE ACCOMMODATED: 1.250 INCHES ALL ENDS IN
•
OPERATING PRESSURE: 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
•
LEG LENGTH: 1.890 INCHES NOMINAL ALL ENDS IN
TECHNICAL CHARACTERISTICS
FURNISHED ITEMS AND QUANTITY3 TUBE COUPLING NUT W/SLEEVE
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONJ514 ASSN STD SINGLE TREATMENT RESPONSE AND MIL-C-81562, TY 1, CL 3 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL
CONNECTION STYLEFLARELESS (TUBE) ALL ENDS
CONNECTION TYPETHREADED EXTERNAL TUBE ALL ENDS
MATERIAL DOCUMENT AND CLASSIFICATION66 FED STD SINGLE MATERIAL RESPONSE OVERALL
NOMINAL OUTSIDE DIAMETER TUBE ACCOMMODATED1.250 INCHES ALL ENDS IN
OPERATING PRESSURE3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
LEG LENGTH1.890 INCHES NOMINAL ALL ENDS IN
NOMINAL THREAD SIZE1.625 INCHES ALL ENDS IN
SEAT ANGLE12.0 DEGREES ALL ENDS
SUBSTITUTES & CROSS-REFERENCES 6
20JBUSReference document
Same NSN cross-reference
Reference document — Secondary reference
MS51811-27ASame NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
MIL-F-18866Reference document
Same NSN cross-reference
Reference document — Secondary reference
20-20 080401CAReference document
Same NSN cross-reference
Reference document — Secondary reference
MS51811-57Reference document
Same NSN cross-reference
Reference document — Secondary reference
MIL-DTL-18866Reference document
Same NSN cross-reference
Reference document — Identification reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Insurance item — stocked against contingency demandNo demilitarization required
Ready to buy MS51811-27?
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 MS51811-27?
MS51811-27 is a ADAPTER,STRAIGHT,TUBE TO BOSS.
What parts can replace MS51811-27?
There are 6 known substitutes for MS51811-27: 20JBUS, MS51811-27A, MIL-F-18866 and 3 more. Substitute compatibility should be verified for your specific system.
What is the NSN for MS51811-27?
MS51811-27 is cataloged in the U.S. Government catalog under NSN 4730-01-006-9931. 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 — MS51811-27

✓ 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.