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91251A581 — SCREW,CAP,SOCKET HEAD

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

91251A581: SCREW,CAP,SOCKET HEAD.

The SCREW,CAP,SOCKET HEAD is a the manufacturer industrial component. Key specifications include material: STEEL OVERALL, head_style: KNURLED NO. 1, head_height: 0.306 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN, thread_class: 2A A, head_diameter: 0.469 INCHES NOMINAL IN, thread_length: 0.639 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN.

This part is cataloged in the U.S. Government catalog under NSN 5305-01-284-0847, 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
91251A581
NSN: 5305-01-284-0847
FSC: 5305 — Screws
CAGE: 39428 — MCMASTER-CARR SUPPLY CO (USA)
SPECIFICATIONS
materialSTEEL OVERALL
head_styleKNURLED NO. 1
head_height0.306 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN
thread_class2A A
head_diameter0.469 INCHES NOMINAL IN
thread_length0.639 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
fastener_length0.750 INCHES NOMINAL IN
hardness_rating39.0 ROCKWELL C MINIMUM AND 45.0 ROCKWELL C MAXIMUM OVERALL
thread_directionRIGHT-HAND
surface_treatmentOXIDE OVERALL
width_across_flats0.250 INCHES NOMINAL IN
internal_drive_styleHEXAGON
NSN5305-01-284-0847
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: 91251A581 · 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: 0.250 INCHES NOMINAL IN
•
HEAD HEIGHT: 0.306 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN
•
FASTENER LENGTH: 0.750 INCHES NOMINAL IN
•
THREAD LENGTH: 0.639 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
•
HARDNESS RATING: 39.0 ROCKWELL C MINIMUM AND 45.0 ROCKWELL C MAXIMUM OVERALL
•
MATERIAL DOCUMENT AND CLASSIFICATION: SAE GRADE 8 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
•
NOMINAL THREAD DIAMETER: 0.312 INCHES IN
•
HEAD STYLE: KNURLED NO. 1
TECHNICAL CHARACTERISTICS
WIDTH ACROSS FLATS0.250 INCHES NOMINAL IN
HEAD HEIGHT0.306 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN
FASTENER LENGTH0.750 INCHES NOMINAL IN
THREAD LENGTH0.639 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
HARDNESS RATING39.0 ROCKWELL C MINIMUM AND 45.0 ROCKWELL C MAXIMUM OVERALL
MATERIAL DOCUMENT AND CLASSIFICATIONSAE GRADE 8 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
NOMINAL THREAD DIAMETER0.312 INCHES IN
HEAD STYLEKNURLED NO. 1
THREAD DIRECTIONRIGHT-HAND
COLORBLACK 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

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 91251A581?
91251A581 is a SCREW,CAP,SOCKET HEAD.
What is the NSN for 91251A581?
91251A581 is cataloged in the U.S. Government catalog under NSN 5305-01-284-0847. This indicates validated use in U.S. government and defense supply chains.
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