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NAS6305U20 — BOLT,CLOSE TOLERANCE

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

NAS6305U20: BOLT,CLOSE TOLERANCE.

The BOLT,CLOSE TOLERANCE is a the manufacturer industrial component. Key specifications include material: IRON ALLOY 660 OVERALL, head_style: UNDERCUT HEXAGON, grip_length: 1.250 INCHES NOMINAL IN, head_height: 0.156 INCHES MINIMUM AND 0.171 INCHES MAXIMUM IN, thread_class: 3A A, grip_diameter: 0.3115 INCHES MINIMUM AND 0.3120 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 5306-01-291-3999, 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
NAS6305U20
NSN: 5306-01-291-3999
FSC: 5306 — Bolts
CAGE: 80205 — NATIONAL AEROSPACE STANDARDS COMMITTEE AEROSPACE INDUSTRIES ASSOCIATION OF AMERICA INC NOT FOR RFQ OR SOLICITATION USE (USA)
SPECIFICATIONS
materialIRON ALLOY 660 OVERALL
head_styleUNDERCUT HEXAGON
grip_length1.250 INCHES NOMINAL IN
head_height0.156 INCHES MINIMUM AND 0.171 INCHES MAXIMUM IN
thread_class3A A
grip_diameter0.3115 INCHES MINIMUM AND 0.3120 INCHES MAXIMUM IN
thread_length0.438 INCHES NOMINAL IN
fastener_length1.688 INCHES NOMINAL IN
thread_directionRIGHT-HAND
surface_treatmentPASSIVATE OVERALL
width_between_flats0.492 INCHES MINIMUM AND 0.502 INCHES MAXIMUM IN
nominal_thread_diameter0.312 INCHES IN
NSN5306-01-291-3999
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: NAS6305U20 · 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
•
HEAD HEIGHT: 0.156 INCHES MINIMUM AND 0.171 INCHES MAXIMUM IN
•
FASTENER LENGTH: 1.688 INCHES NOMINAL IN
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
•
THREAD LENGTH: 0.438 INCHES NOMINAL IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS5731 ASSN STD SINGLE MATERIAL RESPONSE OR AMS5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
•
NOMINAL THREAD DIAMETER: 0.312 INCHES IN
•
HEAD STYLE: UNDERCUT HEXAGON
•
THREAD DIRECTION: RIGHT-HAND
TECHNICAL CHARACTERISTICS
HEAD HEIGHT0.156 INCHES MINIMUM AND 0.171 INCHES MAXIMUM IN
FASTENER LENGTH1.688 INCHES NOMINAL IN
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONQQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
THREAD LENGTH0.438 INCHES NOMINAL IN
MATERIAL DOCUMENT AND CLASSIFICATIONAMS5731 ASSN STD SINGLE MATERIAL RESPONSE OR AMS5737 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
NOMINAL THREAD DIAMETER0.312 INCHES IN
HEAD STYLEUNDERCUT HEXAGON
THREAD DIRECTIONRIGHT-HAND
GRIP LENGTH1.250 INCHES NOMINAL IN
WIDTH BETWEEN FLATS0.492 INCHES MINIMUM AND 0.502 INCHES MAXIMUM IN
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 NAS6305U20?
NAS6305U20 is a BOLT,CLOSE TOLERANCE.
What is the NSN for NAS6305U20?
NAS6305U20 is cataloged in the U.S. Government catalog under NSN 5306-01-291-3999. 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.