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10109378 — WASHER,KEY

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

10109378: WASHER,KEY.

The WASHER,KEY is a the manufacturer industrial component. Key specifications include material: STEEL COMP 4340 OVERALL, hole_diameter: 3.130 INCHES MINIMUM AND 3.140 INCHES MAXIMUM IN, surface_finish: 32.0 MICROINCHES OUTER, hardness_rating: 33.0 ROCKWELL C MAXIMUM, outside_diameter: 3.546 INCHES MINIMUM AND 3.547 INCHES MAXIMUM IN, style_designator: KEY. This part is cataloged in the U.S.

Government catalog under NSN 5310-01-121-0384, 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
10109378
NSN: 5310-01-121-0384
FSC: 5310 — Nuts and Washers
CAGE: A486G — NIMIKKEISTOKESKUS NCB FINLAND (FIN)
SPECIFICATIONS
materialSTEEL COMP 4340 OVERALL
hole_diameter3.130 INCHES MINIMUM AND 3.140 INCHES MAXIMUM IN
surface_finish32.0 MICROINCHES OUTER
hardness_rating33.0 ROCKWELL C MAXIMUM
outside_diameter3.546 INCHES MINIMUM AND 3.547 INCHES MAXIMUM IN
style_designatorKEY
material_thickness0.281 INCHES NOMINAL IN
internal_key_quantity2
minimum_tensile_strength180000 POUNDS PER SQUARE INCH LBS
internal_straight_key_width0.270 INCHES NOMINAL IN
material_document_and_classificationMIL-S-8844,CL 1,COND E2 MIL SPEC SINGLE MATERIAL RESPONSE OR AMS 6414 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
distance_from_centerline_to_top_of_internal_key1.439 INCHES MINIMUM AND 1.449 INCHES MAXIMUM IN
NSN5310-01-121-0384
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: 10109378 · 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
•
SURFACE FINISH: 32.0 MICROINCHES OUTER
•
INTERNAL STRAIGHT KEY WIDTH: 0.270 INCHES NOMINAL IN
•
DISTANCE FROM CENTERLINE TO TOP OF INTERNAL KEY: 1.439 INCHES MINIMUM AND 1.449 INCHES MAXIMUM IN
•
HARDNESS RATING: 33.0 ROCKWELL C MAXIMUM
•
STYLE DESIGNATOR: KEY
•
MATERIAL DOCUMENT AND CLASSIFICATION: MIL-S-8844,CL 1,COND E2 MIL SPEC SINGLE MATERIAL RESPONSE OR AMS 6414 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
•
OUTSIDE DIAMETER: 3.546 INCHES MINIMUM AND 3.547 INCHES MAXIMUM IN
•
MATERIAL THICKNESS: 0.281 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
SURFACE FINISH32.0 MICROINCHES OUTER
INTERNAL STRAIGHT KEY WIDTH0.270 INCHES NOMINAL IN
DISTANCE FROM CENTERLINE TO TOP OF INTERNAL KEY1.439 INCHES MINIMUM AND 1.449 INCHES MAXIMUM IN
HARDNESS RATING33.0 ROCKWELL C MAXIMUM
STYLE DESIGNATORKEY
MATERIAL DOCUMENT AND CLASSIFICATIONMIL-S-8844,CL 1,COND E2 MIL SPEC SINGLE MATERIAL RESPONSE OR AMS 6414 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
OUTSIDE DIAMETER3.546 INCHES MINIMUM AND 3.547 INCHES MAXIMUM IN
MATERIAL THICKNESS0.281 INCHES NOMINAL IN
MINIMUM TENSILE STRENGTH180000 POUNDS PER SQUARE INCH LBS
MATERIALSTEEL COMP 4340 OVERALL
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
74A410533-2001Reference document
Same NSN cross-reference
Reference document — Advisory reference — outside the item-of-supply concept
LIFECYCLE
NSN statusActive· U.S. Government catalog
No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 10109378?
10109378 is a WASHER,KEY.
What parts can replace 10109378?
There is 1 known substitute for 10109378: 74A410533-2001. Substitute compatibility should be verified for your specific system.
What is the NSN for 10109378?
10109378 is cataloged in the U.S. Government catalog under NSN 5310-01-121-0384. 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.