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518103 — NUT,SELF-LOCKING,EXTENDED WASHER

✓ Government record, cited
EMSA · NUT WASHER
PRODUCT OVERVIEW

518103: NUT,SELF-LOCKING,EXTENDED WASHER.

- 100 % portable: the right solution for every problem. - 100 % leak-proof: transports even liquids safely. - 100 % clear: sticker shows the best way to use it.

Key specifications include material: IRON ALLOY 660 OVERALL, nut_style: HEXAGON, thread_class: 3BG, thread_series: UNIFIED NATIONAL JOINT FINE (UNJF), overall_height: 0.206 INCHES MINIMUM AND 0.224 INCHES MAXIMUM IN, locking_feature: PREVAILING TORQUE ALL METAL DESIGN. This part is cataloged in the U.S. Government catalog under NSN 5310-00-931-8540, 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
518103
NSN: 5310-00-931-8540
FSC: 5310 — Nuts and Washers
CAGE: 72962 — HARVARD INDUSTRIES INC (USA)
SPECIFICATIONS
materialIRON ALLOY 660 OVERALL
nut_styleHEXAGON
thread_class3BG
thread_seriesUNIFIED NATIONAL JOINT FINE (UNJF)
overall_height0.206 INCHES MINIMUM AND 0.224 INCHES MAXIMUM IN
locking_featurePREVAILING TORQUE ALL METAL DESIGN
thread_directionRIGHT-HAND
washer_thickness0.044 INCHES MINIMUM AND 0.054 INCHES MAXIMUM IN
surface_treatmentPASSIVATE OVERALL
width_across_flats0.245 INCHES MINIMUM AND 0.252 INCHES MAXIMUM IN
nominal_thread_size0.190 INCHES IN
washer_outside_diameter0.470 INCHES MINIMUM AND 0.480 INCHES MAXIMUM IN
NSN5310-00-931-8540
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: 518103 · EMSA ⚠ 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: 0.470 INCHES MINIMUM AND 0.480 INCHES MAXIMUM IN
•
WIDTH ACROSS FLATS: 0.245 INCHES MINIMUM AND 0.252 INCHES MAXIMUM IN
•
THREAD SERIES: UNIFIED NATIONAL JOINT FINE (UNJF)
•
WASHER THICKNESS: 0.044 INCHES MINIMUM AND 0.054 INCHES MAXIMUM IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
•
THREAD DIRECTION: RIGHT-HAND
•
NOMINAL THREAD SIZE: 0.190 INCHES IN
TECHNICAL CHARACTERISTICS
OVERALL HEIGHT0.206 INCHES MINIMUM AND 0.224 INCHES MAXIMUM IN
WASHER OUTSIDE DIAMETER0.470 INCHES MINIMUM AND 0.480 INCHES MAXIMUM IN
WIDTH ACROSS FLATS0.245 INCHES MINIMUM AND 0.252 INCHES MAXIMUM IN
THREAD SERIESUNIFIED NATIONAL JOINT FINE (UNJF)
WASHER THICKNESS0.044 INCHES MINIMUM AND 0.054 INCHES MAXIMUM IN
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
THREAD DIRECTIONRIGHT-HAND
NOMINAL THREAD SIZE0.190 INCHES IN
LOCKING FEATUREPREVAILING TORQUE ALL METAL DESIGN
SURFACE TREATMENTPASSIVATE OVERALL
OTHER ITEMS IN FSC 5310 — Nuts and Washers
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5310-00-000-0040 5310-00-000-0077 5310-00-000-0079 5310-00-000-1146 5310-00-000-3815 5310-00-000-4532 5310-00-000-4540
SUBSTITUTES & CROSS-REFERENCES

No substitute or cross-reference records for this part.

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 518103?
518103 is a NUT,SELF-LOCKING,EXTENDED WASHER manufactured by EMSA.
What is the NSN for 518103?
518103 is cataloged in the U.S. Government catalog under NSN 5310-00-931-8540. 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.