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F18421L — NUT SPACER,PLATE

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

F18421L: NUT SPACER,PLATE.

The NUT SPACER,PLATE is a the manufacturer industrial component. Key specifications include material: IRON ALLOY 660 OVERALL, plate_width: 0.740 INCHES MAXIMUM IN, plate_thickness: 0.046 INCHES MINIMUM AND 0.054 INCHES MAXIMUM IN, surface_treatment: PASSIVATE OVERALL, thru-hole_diameter: 0.245 INCHES MINIMUM AND 0.255 INCHES MAXIMUM IN, nut_mounting_provision: STRAIGHT HOLES. This part is cataloged in the U.S.

Government catalog under NSN 5310-01-260-3575, 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
F18421L
NSN: 5310-01-260-3575
FSC: 5310 — Nuts and Washers
CAGE: 80539 — SPS TECHNOLOGIES, LLC DBA AEROSPACE FASTENERS GROUP DIV AEROSPACE - SANTA ANA (USA)
SPECIFICATIONS
materialIRON ALLOY 660 OVERALL
plate_width0.740 INCHES MAXIMUM IN
plate_thickness0.046 INCHES MINIMUM AND 0.054 INCHES MAXIMUM IN
surface_treatmentPASSIVATE OVERALL
thru-hole_diameter0.245 INCHES MINIMUM AND 0.255 INCHES MAXIMUM IN
nut_mounting_provisionSTRAIGHT HOLES
mounting_hole_arrangement_style2 HOLES
material_document_and_classificationAMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
NSN5310-01-260-3575
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: F18421L · 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
•
PLATE THICKNESS: 0.046 INCHES MINIMUM AND 0.054 INCHES MAXIMUM IN
•
PLATE WIDTH: 0.740 INCHES MAXIMUM IN
•
MOUNTING HOLE ARRANGEMENT STYLE: 2 HOLES
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
•
THRU-HOLE DIAMETER: 0.245 INCHES MINIMUM AND 0.255 INCHES MAXIMUM IN
•
SURFACE TREATMENT: PASSIVATE OVERALL
•
MATERIAL: IRON ALLOY 660 OVERALL
•
NUT MOUNTING PROVISION: STRAIGHT HOLES
TECHNICAL CHARACTERISTICS
PLATE THICKNESS0.046 INCHES MINIMUM AND 0.054 INCHES MAXIMUM IN
PLATE WIDTH0.740 INCHES MAXIMUM IN
MOUNTING HOLE ARRANGEMENT STYLE2 HOLES
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
THRU-HOLE DIAMETER0.245 INCHES MINIMUM AND 0.255 INCHES MAXIMUM IN
SURFACE TREATMENTPASSIVATE OVERALL
MATERIALIRON ALLOY 660 OVERALL
NUT MOUNTING PROVISIONSTRAIGHT HOLES
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
ST3M443-6DReference document
Same NSN cross-reference
Reference document — Vendor item drawing reference
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 F18421L?
F18421L is a NUT SPACER,PLATE.
What parts can replace F18421L?
There is 1 known substitute for F18421L: ST3M443-6D. Substitute compatibility should be verified for your specific system.
What is the NSN for F18421L?
F18421L is cataloged in the U.S. Government catalog under NSN 5310-01-260-3575. 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.