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KFN512C4 — NUT,SELF-LOCKING,ASSEMBLED WASHE

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

KFN512C4: NUT,SELF-LOCKING,ASSEMBLED WASHE.

NUT,SELF-LOCKING,ASSEMBLED WASHE. Key specifications include material: STEEL CORROSION RESISTING WASHER, nut_style: FLAT WITH TURNED UP EDGE, thread_class: 3B, thread_series: UNIFIED NATIONAL JOINT FINE (UNJF), overall_height: 0.340 INCHES MAXIMUM IN, hardness_rating: 33.0 ROCKWELL C MINIMUM AND 44.0 ROCKWELL C MAXIMUM. This part is cataloged in the U.S.

Government catalog under NSN 5310-01-475-6869, 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
KFN512C4
NSN: 5310-01-475-6869
FSC: 5310 — Nuts and Washers
CAGE: 56878 — SPS TECHNOLOGIES, LLC DBA PB FASTENERS (USA)
SPECIFICATIONS
materialSTEEL CORROSION RESISTING WASHER
nut_styleFLAT WITH TURNED UP EDGE
thread_class3B
thread_seriesUNIFIED NATIONAL JOINT FINE (UNJF)
overall_height0.340 INCHES MAXIMUM IN
hardness_rating33.0 ROCKWELL C MINIMUM AND 44.0 ROCKWELL C MAXIMUM
locking_featurePREVAILING TORQUE ALL METAL DESIGN
thread_directionRIGHT-HAND
surface_treatmentCADMIUM AND CHROMATE OVERALL
width_across_flats0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN
nominal_thread_size0.250 INCHES IN
counterbore_diameter0.267 INCHES MINIMUM AND 0.272 INCHES MAXIMUM FIRST END IN
NSN5310-01-475-6869
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: KFN512C4 · 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: 0.460 INCHES MAXIMUM IN
•
WIDTH ACROSS FLATS: 0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: QQ-P-416,TYPE II,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
•
THREAD SERIES: UNIFIED NATIONAL JOINT FINE (UNJF)
•
HARDNESS RATING: 33.0 ROCKWELL C MINIMUM AND 44.0 ROCKWELL C MAXIMUM
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 5732,A-286 ASSN STD 1ST MATERIAL RESPONSE OR AMS 5737,A-286 ASSN STD 2ND MATERIAL RESPONSE NUT A
TECHNICAL CHARACTERISTICS
OVERALL HEIGHT0.340 INCHES MAXIMUM IN
WASHER OUTSIDE DIAMETER0.460 INCHES MAXIMUM IN
WIDTH ACROSS FLATS0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONQQ-P-416,TYPE II,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
THREAD SERIESUNIFIED NATIONAL JOINT FINE (UNJF)
HARDNESS RATING33.0 ROCKWELL C MINIMUM AND 44.0 ROCKWELL C MAXIMUM
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 5732,A-286 ASSN STD 1ST MATERIAL RESPONSE OR AMS 5737,A-286 ASSN STD 2ND MATERIAL RESPONSE NUT A
MATERIAL DOCUMENT AND CLASSIFICATIONQQ-S-763,300 SERIES FED SPEC 1ST MATERIAL RESPONSE OR QQ-S-766,300 SERIES FED SPEC 2ND MATERIAL RESPONSE WASHER
NUT COUNTERBORE DEPTH0.107 INCHES MINIMUM AND 0.117 INCHES MAXIMUM FIRST END IN
THREAD DIRECTIONRIGHT-HAND
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 1
03A136W4CSame NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
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 KFN512C4?
KFN512C4 is a NUT,SELF-LOCKING,ASSEMBLED WASHE.
What parts can replace KFN512C4?
There is 1 known substitute for KFN512C4: 03A136W4C. Substitute compatibility should be verified for your specific system.
What is the NSN for KFN512C4?
KFN512C4 is cataloged in the U.S. Government catalog under NSN 5310-01-475-6869. 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.