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720561-5 — WASHER,LOCK

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

720561-5: WASHER,LOCK.

The WASHER,LOCK is a the manufacturer industrial component. Key specifications include material: STEEL CORROSION RESISTING OVERALL, hole_diameter: 0.141 INCHES MINIMUM AND 0.150 INCHES MAXIMUM IN, outside_diameter: 0.275 INCHES MINIMUM AND 0.285 INCHES MAXIMUM IN, style_designator: FLAT INTERNAL TEETH, surface_treatment: OXIDE FILM OVERALL, material_thickness: 0.016 INCHES MINIMUM AND 0.020 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 5310-00-655-6842, 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
720561-5
NSN: 5310-00-655-6842
FSC: 5310 — Nuts and Washers
CAGE: 56232 — LOCKHEED MARTIN CORPORATION DIV RMS - MITCHEL FIELD (USA)
SPECIFICATIONS
materialSTEEL CORROSION RESISTING OVERALL
hole_diameter0.141 INCHES MINIMUM AND 0.150 INCHES MAXIMUM IN
outside_diameter0.275 INCHES MINIMUM AND 0.285 INCHES MAXIMUM IN
style_designatorFLAT INTERNAL TEETH
surface_treatmentOXIDE FILM OVERALL
material_thickness0.016 INCHES MINIMUM AND 0.020 INCHES MAXIMUM IN
NSN5310-00-655-6842
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: 720561-5 · 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
•
STYLE DESIGNATOR: FLAT INTERNAL TEETH
•
OUTSIDE DIAMETER: 0.275 INCHES MINIMUM AND 0.285 INCHES MAXIMUM IN
•
MATERIAL THICKNESS: 0.016 INCHES MINIMUM AND 0.020 INCHES MAXIMUM IN
•
COLOR: BLACK OVERALL
•
SURFACE TREATMENT: OXIDE FILM OVERALL
•
MATERIAL: STEEL CORROSION RESISTING OVERALL
•
HOLE DIAMETER: 0.141 INCHES MINIMUM AND 0.150 INCHES MAXIMUM IN
TECHNICAL CHARACTERISTICS
STYLE DESIGNATORFLAT INTERNAL TEETH
OUTSIDE DIAMETER0.275 INCHES MINIMUM AND 0.285 INCHES MAXIMUM IN
MATERIAL THICKNESS0.016 INCHES MINIMUM AND 0.020 INCHES MAXIMUM IN
COLORBLACK OVERALL
SURFACE TREATMENTOXIDE FILM OVERALL
MATERIALSTEEL CORROSION RESISTING OVERALL
HOLE DIAMETER0.141 INCHES MINIMUM AND 0.150 INCHES MAXIMUM IN
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
No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 720561-5?
720561-5 is a WASHER,LOCK.
What is the NSN for 720561-5?
720561-5 is cataloged in the U.S. Government catalog under NSN 5310-00-655-6842. 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.