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66-14778-1 — BOLT,INTERNAL WRENCHING

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

66-14778-1: BOLT,INTERNAL WRENCHING.

The BOLT,INTERNAL WRENCHING is a the manufacturer industrial component. Key specifications include material: ALUMINUM ALLOY 2024 OVERALL, head_style: BEVEL-CONICAL, head_height: 0.343 INCHES NOMINAL IN, thread_class: 3A A, head_diameter: 0.615 INCHES MINIMUM AND 0.625 INCHES MAXIMUM IN, thread_length: 0.673 INCHES MINIMUM AND 0.703 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 5306-01-079-7245, 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
66-14778-1
NSN: 5306-01-079-7245
FSC: 5306 — Bolts
CAGE: 17765 — THE BOEING COMPANY DIV COMMERCIAL (USA)
SPECIFICATIONS
materialALUMINUM ALLOY 2024 OVERALL
head_styleBEVEL-CONICAL
head_height0.343 INCHES NOMINAL IN
thread_class3A A
head_diameter0.615 INCHES MINIMUM AND 0.625 INCHES MAXIMUM IN
thread_length0.673 INCHES MINIMUM AND 0.703 INCHES MAXIMUM IN
fastener_length4.985 INCHES MINIMUM AND 5.015 INCHES MAXIMUM IN
thread_directionRIGHT-HAND
surface_treatmentANODIZE OVERALL
width_across_flats0.3755 INCHES MINIMUM AND 0.3785 INCHES MAXIMUM IN
internal_drive_styleHEXAGON
nominal_thread_diameter0.375 INCHES IN
NSN5306-01-079-7245
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: 66-14778-1 · OEM ⚠ VERIFY BEFORE ORDERING Verify thread pitch before ordering — metric (M8×1.25) ≠ imperial (5/16-18). Wrong thread = wrong part. Grade/class stamped on bolt head determines tensile strength ✓ BROKER TIP Grade/class stamped on head determines tensile strength. Grade 8 > Grade 5 > Grade 2. Always confirm head marking matches specification requirement PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
WIDTH ACROSS FLATS: 0.3755 INCHES MINIMUM AND 0.3785 INCHES MAXIMUM IN
•
HEAD HEIGHT: 0.343 INCHES NOMINAL IN
•
FASTENER LENGTH: 4.985 INCHES MINIMUM AND 5.015 INCHES MAXIMUM IN
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: MIL-A-8625 TY 1 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL
•
THREAD LENGTH: 0.673 INCHES MINIMUM AND 0.703 INCHES MAXIMUM IN
•
SHANK UNTHREADED HOLE DIAMETER: 0.106 INCHES MINIMUM AND 0.111 INCHES MAXIMUM FIRST HOLE IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: QQ-A-200/3 TEMPER T4 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
•
NOMINAL THREAD DIAMETER: 0.375 INCHES IN
TECHNICAL CHARACTERISTICS
WIDTH ACROSS FLATS0.3755 INCHES MINIMUM AND 0.3785 INCHES MAXIMUM IN
HEAD HEIGHT0.343 INCHES NOMINAL IN
FASTENER LENGTH4.985 INCHES MINIMUM AND 5.015 INCHES MAXIMUM IN
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONMIL-A-8625 TY 1 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL
THREAD LENGTH0.673 INCHES MINIMUM AND 0.703 INCHES MAXIMUM IN
SHANK UNTHREADED HOLE DIAMETER0.106 INCHES MINIMUM AND 0.111 INCHES MAXIMUM FIRST HOLE IN
MATERIAL DOCUMENT AND CLASSIFICATIONQQ-A-200/3 TEMPER T4 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
NOMINAL THREAD DIAMETER0.375 INCHES IN
HEAD STYLEBEVEL-CONICAL
THREAD DIRECTIONRIGHT-HAND
OTHER ITEMS IN FSC 5306 — Bolts
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5306-00-001-1276 5306-00-001-1949 5306-00-001-1988 5306-00-001-1989 5306-00-001-1990 5306-00-001-1991 5306-00-001-1993 5306-00-001-2017
SUBSTITUTES & CROSS-REFERENCES

No substitute or cross-reference records for this part.

LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Insurance item — stocked against contingency demandNo demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 66-14778-1?
66-14778-1 is a BOLT,INTERNAL WRENCHING.
What is the NSN for 66-14778-1?
66-14778-1 is cataloged in the U.S. Government catalog under NSN 5306-01-079-7245. 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.