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91257A939 — BOLT,MACHINE

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

91257A939: BOLT,MACHINE.

The BOLT,MACHINE is a the manufacturer industrial component. Key specifications include material: STEEL OVERALL, head_style: HEXAGON, head_height: 0.546 INCHES NOMINAL IN, thread_class: 2A A, thread_length: 2.000 INCHES MINIMUM AND 2.562 INCHES MAXIMUM IN, fastener_length: 4.500 INCHES NOMINAL IN. This part is cataloged in the U.S.

Government catalog under NSN 5306-01-601-4288, 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
91257A939
NSN: 5306-01-601-4288
FSC: 5306 — Bolts
CAGE: 39428 — MCMASTER-CARR SUPPLY CO (USA)
SPECIFICATIONS
materialSTEEL OVERALL
head_styleHEXAGON
head_height0.546 INCHES NOMINAL IN
thread_class2A A
thread_length2.000 INCHES MINIMUM AND 2.562 INCHES MAXIMUM IN
fastener_length4.500 INCHES NOMINAL IN
hardness_rating33.0 ROCKWELL C MINIMUM OVERALL
thread_directionRIGHT-HAND
surface_treatmentCHROMATE ZINC OVERALL
width_between_flats1.312 INCHES NOMINAL IN
nominal_thread_diameter0.875 INCHES IN
minimum_tensile_strength150000 POUNDS PER SQUARE INCH LBS
NSN5306-01-601-4288
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: 91257A939 · 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: 0.546 INCHES NOMINAL IN
•
FASTENER LENGTH: 4.500 INCHES NOMINAL IN
•
THREAD LENGTH: 2.000 INCHES MINIMUM AND 2.562 INCHES MAXIMUM IN
•
HARDNESS RATING: 33.0 ROCKWELL C MINIMUM OVERALL
•
NOMINAL THREAD DIAMETER: 0.875 INCHES IN
•
HEAD STYLE: HEXAGON
•
THREAD DIRECTION: RIGHT-HAND
•
WIDTH BETWEEN FLATS: 1.312 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
HEAD HEIGHT0.546 INCHES NOMINAL IN
FASTENER LENGTH4.500 INCHES NOMINAL IN
THREAD LENGTH2.000 INCHES MINIMUM AND 2.562 INCHES MAXIMUM IN
HARDNESS RATING33.0 ROCKWELL C MINIMUM OVERALL
NOMINAL THREAD DIAMETER0.875 INCHES IN
HEAD STYLEHEXAGON
THREAD DIRECTIONRIGHT-HAND
WIDTH BETWEEN FLATS1.312 INCHES NOMINAL IN
COLORYELLOW OVERALL
SURFACE TREATMENTCHROMATE ZINC OVERALL
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
No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 91257A939?
91257A939 is a BOLT,MACHINE.
What is the NSN for 91257A939?
91257A939 is cataloged in the U.S. Government catalog under NSN 5306-01-601-4288. 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.