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ST3M788-8 — NUT,SELF-LOCKING,EXTENDED WASHER

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

ST3M788-8: NUT,SELF-LOCKING,EXTENDED WASHER.

NUT,SELF-LOCKING,EXTENDED WASHER. Key specifications include material: IRON ALLOY 660 OVERALL, nut_style: SLOTTED HEXAGON, lubrication: DRY FILM LUBRICANT, temp_rating: 450.0 FAHRENHEIT MAXIMUM DEGF, thread_class: 3B, thread_series: UNIFIED NATIONAL JOINT FINE (UNJF). This part is cataloged in the U.S.

Government catalog under NSN 5310-01-134-5784, 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
ST3M788-8
NSN: 5310-01-134-5784
FSC: 5310 — Nuts and Washers
CAGE: 76301 — THE BOEING COMPANY DIV DEFENSE (USA)
SPECIFICATIONS
materialIRON ALLOY 660 OVERALL
nut_styleSLOTTED HEXAGON
lubricationDRY FILM LUBRICANT
temp_rating450.0 FAHRENHEIT MAXIMUM DEGF
thread_class3B
thread_seriesUNIFIED NATIONAL JOINT FINE (UNJF)
overall_height0.235 INCHES MINIMUM AND 0.265 INCHES MAXIMUM IN
locking_featurePREVAILING TORQUE ALL METAL DESIGN
thread_directionRIGHT-HAND
washer_thickness0.030 INCHES NOMINAL IN
width_across_flats0.633 INCHES NOMINAL IN
nominal_thread_size0.500 INCHES IN
NSN5310-01-134-5784
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: ST3M788-8 · 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
•
LUBRICATION: DRY FILM LUBRICANT
•
WASHER OUTSIDE DIAMETER: 0.725 INCHES MINIMUM AND 0.770 INCHES MAXIMUM IN
•
WIDTH ACROSS FLATS: 0.633 INCHES NOMINAL IN
•
THREAD SERIES: UNIFIED NATIONAL JOINT FINE (UNJF)
•
TEMP RATING: 450.0 FAHRENHEIT MAXIMUM DEGF
•
WASHER THICKNESS: 0.030 INCHES NOMINAL IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
TECHNICAL CHARACTERISTICS
LUBRICATIONDRY FILM LUBRICANT
OVERALL HEIGHT0.235 INCHES MINIMUM AND 0.265 INCHES MAXIMUM IN
WASHER OUTSIDE DIAMETER0.725 INCHES MINIMUM AND 0.770 INCHES MAXIMUM IN
WIDTH ACROSS FLATS0.633 INCHES NOMINAL IN
THREAD SERIESUNIFIED NATIONAL JOINT FINE (UNJF)
TEMP RATING450.0 FAHRENHEIT MAXIMUM DEGF
WASHER THICKNESS0.030 INCHES NOMINAL IN
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 5737 ASSN STD SINGLE MATERIAL RESPONSE OR AMS 5525 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
THREAD DIRECTIONRIGHT-HAND
NOMINAL THREAD SIZE0.500 INCHES IN
SUBSTITUTES & CROSS-REFERENCES 2
10109706Reference document
Same NSN cross-reference
Reference document — Informative reference only
E12589-8Reference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is ST3M788-8?
ST3M788-8 is a NUT,SELF-LOCKING,EXTENDED WASHER.
What parts can replace ST3M788-8?
There are 2 known substitutes for ST3M788-8: 10109706, E12589-8. Substitute compatibility should be verified for your specific system.
What is the NSN for ST3M788-8?
ST3M788-8 is cataloged in the U.S. Government catalog under NSN 5310-01-134-5784. 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.