PartsTable
Technical Data Sheet
PartsTable / COMPONENT / 21FC428
21FC428 ✓ Verified by PartsTable
— · NUT WASHER
WHAT YOU NEED TO KNOW
Match nut grade to bolt grade for full strength Lock nuts prevent loosening under vibration
Don't mix grades — weakens the joint
PRODUCT OVERVIEW

The NUT,SELF-LOCKING,HEXAGON is a the manufacturer industrial component. Key specifications include material: STEEL OVERALL, nut_style: HEXAGON, nut_height: 0.320 INCHES MAXIMUM IN, lubrication: SOLUBLE LUBRICANT, thread_class: 3B, thread_series: UNIFIED NATIONAL JOINT FINE (UNJF). This product is currently in active production with full OEM support.

This part is cataloged in the Federal Logistics Information System (FLIS) under NSN 5310-00-035-5296, 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
21FC428
NSN: 5310-00-035-5296
FSC: 5310
CAGE: 99207 — GENERAL ELECTRIC COMPANY DBA GE AEROSPACE (USA)
SPECIFICATIONS
materialSTEEL OVERALL
nut_styleHEXAGON
nut_height0.320 INCHES MAXIMUM IN
lubricationSOLUBLE LUBRICANT
thread_class3B
thread_seriesUNIFIED NATIONAL JOINT FINE (UNJF)
locking_featurePREVAILING TORQUE ALL METAL DESIGN
thread_directionRIGHT-HAND
surface_treatmentCADMIUM OVERALL
width_across_flats0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN
nominal_thread_size0.250 INCHES IN
bearing_surface_typeCHAMFERED
NSN5310-00-035-5296
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: 21FC428 · 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
•
NUT HEIGHT: 0.270 INCHES MINIMUM AND 0.290 INCHES MAXIMUM IN
•
NUT STYLE: HEXAGON
•
NOMINAL THREAD SIZE: 0.250 INCHES IN
•
BEARING SURFACE TYPE: CHAMFERED
•
TEMP RATING: 550.0 FAHRENHEIT NOMINAL DEGF
•
THREAD CLASS: 3B
•
THREAD DIRECTION: RIGHT-HAND
•
MATERIAL: STEEL OVERALL
TECHNICAL CHARACTERISTICS (FLIS)
NUT HEIGHT0.270 INCHES MINIMUM AND 0.290 INCHES MAXIMUM IN
NUT STYLEHEXAGON
NOMINAL THREAD SIZE0.250 INCHES IN
BEARING SURFACE TYPECHAMFERED
TEMP RATING550.0 FAHRENHEIT NOMINAL DEGF
THREAD CLASS3B
THREAD DIRECTIONRIGHT-HAND
MATERIALSTEEL OVERALL
THREAD QUANTITY PER INCH28
LOCKING FEATUREPREVAILING TORQUE ALL METAL DESIGN
VERIFIED SUBSTITUTES & CROSS-REFERENCES 2
21FC428Interchangeable
interchangeable cross-reference
interchangeable
50680Interchangeable
interchangeable cross-reference
interchangeable
LIFECYCLE
StatusACTIVE
AvailabilityOEM and secondary market
RoHS CompliantEAR99Not HAZMAT
Ready to buy 21FC428?
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 21FC428?
21FC428 is a NUT,SELF-LOCKING,HEXAGON.
What parts can replace 21FC428?
There are 2 known substitutes for 21FC428: 21FC428, 50680. Substitute compatibility should be verified for your specific system.
What is the NSN for 21FC428?
21FC428 is cataloged in the Federal Logistics Information System (FLIS) under NSN 5310-00-035-5296. This indicates validated use in U.S. government and defense supply chains.
Community Feedback
Comments (0)
No comments yet. Be the first to share what you know.
Leave a Comment
Comments are reviewed before appearing. You will receive an email to verify before your comment appears.

Request a Quote — 21FC428

✓ Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com
Last verified: July 2026