PartsTable
Technical Data Sheet
Download PDF

WA21-4 — WASHER,LOCK

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

WA21-4: WASHER,LOCK.

The WASHER,LOCK is a the manufacturer industrial component. Key specifications include material: STEEL OVERALL, hole_diameter: 0.168 INCHES MINIMUM AND 0.176 INCHES MAXIMUM IN, outside_diameter: 0.370 INCHES MINIMUM AND 0.381 INCHES MAXIMUM IN, style_designator: FLAT EXTERNAL TEETH, material_thickness: 0.020 INCHES NOMINAL IN. This part is cataloged in the U.S.

Government catalog under NSN 5310-00-641-9379, 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
WA21-4
NSN: 5310-00-641-9379
FSC: 5310 — Nuts and Washers
CAGE: 24956 — UNITED TECHNOLOGIES CORP ELECTRO SYSTEMS INC (USA)
SPECIFICATIONS
materialSTEEL OVERALL
hole_diameter0.168 INCHES MINIMUM AND 0.176 INCHES MAXIMUM IN
outside_diameter0.370 INCHES MINIMUM AND 0.381 INCHES MAXIMUM IN
style_designatorFLAT EXTERNAL TEETH
material_thickness0.020 INCHES NOMINAL IN
NSN5310-00-641-9379
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: WA21-4 · 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
•
STYLE DESIGNATOR: FLAT EXTERNAL TEETH
•
OUTSIDE DIAMETER: 0.370 INCHES MINIMUM AND 0.381 INCHES MAXIMUM IN
•
MATERIAL THICKNESS: 0.020 INCHES NOMINAL IN
•
MATERIAL: STEEL OVERALL
•
HOLE DIAMETER: 0.168 INCHES MINIMUM AND 0.176 INCHES MAXIMUM IN
TECHNICAL CHARACTERISTICS
STYLE DESIGNATORFLAT EXTERNAL TEETH
OUTSIDE DIAMETER0.370 INCHES MINIMUM AND 0.381 INCHES MAXIMUM IN
MATERIAL THICKNESS0.020 INCHES NOMINAL IN
MATERIALSTEEL OVERALL
HOLE DIAMETER0.168 INCHES MINIMUM AND 0.176 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
Ready to buy WA21-4?
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 WA21-4?
WA21-4 is a WASHER,LOCK.
What is the NSN for WA21-4?
WA21-4 is cataloged in the U.S. Government catalog under NSN 5310-00-641-9379. 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 — WA21-4

✓ 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.