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H19943-4 — NUT,SELF-LOCKING,EXTENDED WASHER

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

H19943-4: NUT,SELF-LOCKING,EXTENDED WASHER.

NUT,SELF-LOCKING,EXTENDED WASHER. Key specifications include material: IRON ALLOY 660 OVERALL, nut_style: DOUBLE HEXAGON, thread_class: 3BG, thread_series: UNIFIED NATIONAL JOINT FINE (UNJF), overall_height: 0.282 INCHES MINIMUM AND 0.292 INCHES MAXIMUM IN, locking_feature: PREVAILING TORQUE ALL METAL DESIGN. This part is cataloged in the U.S.

Government catalog under NSN 5310-00-975-1618, 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
H19943-4
NSN: 5310-00-975-1618
FSC: 5310 — Nuts and Washers
CAGE: 15653 — HOWMET GLOBAL FASTENING SYSTEMS INC (USA)
SPECIFICATIONS
materialIRON ALLOY 660 OVERALL
nut_styleDOUBLE HEXAGON
thread_class3BG
thread_seriesUNIFIED NATIONAL JOINT FINE (UNJF)
overall_height0.282 INCHES MINIMUM AND 0.292 INCHES MAXIMUM IN
locking_featurePREVAILING TORQUE ALL METAL DESIGN
thread_directionRIGHT-HAND
washer_thickness0.035 INCHES MINIMUM AND 0.045 INCHES MAXIMUM IN
precious_materialSILVER
surface_treatmentSILVER OVERALL
width_across_flats0.304 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN
nominal_thread_size0.250 INCHES IN
NSN5310-00-975-1618
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: H19943-4 · OEM ⚠ VERIFY BEFORE ORDERING Grade matters for torque spec — don't mix grades. A Grade 5 nut on a Grade 8 bolt weakens the joint. Lock nuts, wing nuts, and castle nuts are NOT interchangeable with standard hex ✓ BROKER TIP Match nut to bolt thread class and material. Stainless bolt + zinc nut = galvanic corrosion. Always verify finish matches (plain, zinc, hot-dip galvanized) PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
WASHER OUTSIDE DIAMETER: 0.399 INCHES MINIMUM AND 0.409 INCHES MAXIMUM IN
•
WIDTH ACROSS FLATS: 0.304 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN
•
THREAD SERIES: UNIFIED NATIONAL JOINT FINE (UNJF)
•
PRECIOUS MATERIAL: SILVER
•
WASHER THICKNESS: 0.035 INCHES MINIMUM AND 0.045 INCHES MAXIMUM IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 5735 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
•
THREAD DIRECTION: RIGHT-HAND
TECHNICAL CHARACTERISTICS
OVERALL HEIGHT0.282 INCHES MINIMUM AND 0.292 INCHES MAXIMUM IN
WASHER OUTSIDE DIAMETER0.399 INCHES MINIMUM AND 0.409 INCHES MAXIMUM IN
WIDTH ACROSS FLATS0.304 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN
THREAD SERIESUNIFIED NATIONAL JOINT FINE (UNJF)
PRECIOUS MATERIALSILVER
WASHER THICKNESS0.035 INCHES MINIMUM AND 0.045 INCHES MAXIMUM IN
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 5735 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
THREAD DIRECTIONRIGHT-HAND
NOMINAL THREAD SIZE0.250 INCHES IN
LOCKING FEATUREPREVAILING TORQUE ALL METAL DESIGN
SUBSTITUTES & CROSS-REFERENCES 6
490275Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
488995Reference document
Same NSN cross-reference
Reference document — Secondary reference
490274Reference document
Same NSN cross-reference
Reference document — Secondary reference
LH6629-048KReference document
Same NSN cross-reference
Reference document — Secondary reference
ST1184-10Reference document
Same NSN cross-reference
Reference document — Secondary reference
VN1497BA048Reference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusCancelled· U.S. Government catalog
Acquisition advice: Normally procured from the manufacturer (OEM)No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is H19943-4?
H19943-4 is a NUT,SELF-LOCKING,EXTENDED WASHER.
What parts can replace H19943-4?
There are 6 known substitutes for H19943-4: 490275, 488995, 490274 and 3 more. Substitute compatibility should be verified for your specific system.
What is the NSN for H19943-4?
H19943-4 is cataloged in the U.S. Government catalog under NSN 5310-00-975-1618. This indicates validated use in U.S. government and defense supply chains.
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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.