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MCMAS-91257A979 — SCREW,CAP,HEXAGON HEAD

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

MCMAS-91257A979: SCREW,CAP,HEXAGON HEAD.

The SCREW,CAP,HEXAGON HEAD is a the manufacturer industrial component. Key specifications include material: STEEL OVERALL, head_style: HEXAGON, head_height: 0.672 INCHES NOMINAL IN, thread_length: 8.50 INCHES NOMINAL IN, fastener_length: 9.17 INCHES NOMINAL IN, thread_direction: RIGHT-HAND. This part is cataloged in the U.S.

Government catalog under NSN 5305-01-666-0622, 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
MCMAS-91257A979
NSN: 5305-01-666-0622
FSC: 5305 — Screws
CAGE: 4F7L1 — BROTHERS BODY AND EQUIPMENT, LLC (USA)
SPECIFICATIONS
materialSTEEL OVERALL
head_styleHEXAGON
head_height0.672 INCHES NOMINAL IN
thread_length8.50 INCHES NOMINAL IN
fastener_length9.17 INCHES NOMINAL IN
thread_directionRIGHT-HAND
surface_treatmentCHROMATE ZINC OVERALL
width_between_flats1.50 INCHES NOMINAL IN
end_item_identificationNSN 3895-016094511
minimum_tensile_strength150000 POUNDS PER SQUARE INCH LBS
thread_series_designatorUNIFIED NATIONAL COARSE (UNC)
NSN5305-01-666-0622
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: MCMAS-91257A979 · 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: 0.672 INCHES NOMINAL IN
•
FASTENER LENGTH: 9.17 INCHES NOMINAL IN
•
THREAD LENGTH: 8.50 INCHES NOMINAL IN
•
HEAD STYLE: HEXAGON
•
THREAD DIRECTION: RIGHT-HAND
•
WIDTH BETWEEN FLATS: 1.50 INCHES NOMINAL IN
•
SURFACE TREATMENT: CHROMATE ZINC OVERALL
•
MINIMUM TENSILE STRENGTH: 150000 POUNDS PER SQUARE INCH LBS
TECHNICAL CHARACTERISTICS
HEAD HEIGHT0.672 INCHES NOMINAL IN
FASTENER LENGTH9.17 INCHES NOMINAL IN
THREAD LENGTH8.50 INCHES NOMINAL IN
HEAD STYLEHEXAGON
THREAD DIRECTIONRIGHT-HAND
WIDTH BETWEEN FLATS1.50 INCHES NOMINAL IN
SURFACE TREATMENTCHROMATE ZINC OVERALL
MINIMUM TENSILE STRENGTH150000 POUNDS PER SQUARE INCH LBS
END ITEM IDENTIFICATIONNSN 3895-016094511
MATERIALSTEEL OVERALL
OTHER ITEMS IN FSC 5305 — Screws
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5305-00-001-5016 5305-00-001-9160 5305-00-001-9629 5305-00-001-9742 5305-00-001-9768 5305-00-003-4306 5305-00-003-6694 5305-00-003-6753
SUBSTITUTES & CROSS-REFERENCES 1
91257A979Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
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 MCMAS-91257A979?
MCMAS-91257A979 is a SCREW,CAP,HEXAGON HEAD.
What parts can replace MCMAS-91257A979?
There is 1 known substitute for MCMAS-91257A979: 91257A979. Substitute compatibility should be verified for your specific system.
What is the NSN for MCMAS-91257A979?
MCMAS-91257A979 is cataloged in the U.S. Government catalog under NSN 5305-01-666-0622. 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.