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90185A621 — BOLT,SQUARE NECK

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

90185A621: BOLT,SQUARE NECK.

The BOLT,SQUARE NECK is a the manufacturer industrial component. Key specifications include material: STEEL OVERALL, head_style: FLAT FILLISTER, neck_width: 0.388 INCHES NOMINAL IN, head_height: 0.208 INCHES NOMINAL IN, neck_length: 0.219 INCHES NOMINAL IN, thread_class: 2A A. This part is cataloged in the U.S.

Government catalog under NSN 5306-01-592-1998, 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
90185A621
NSN: 5306-01-592-1998
FSC: 5306 — Bolts
CAGE: 2V507 — MCMASTER-CARR SUPPLY COMPANY (USA)
SPECIFICATIONS
materialSTEEL OVERALL
head_styleFLAT FILLISTER
neck_width0.388 INCHES NOMINAL IN
head_height0.208 INCHES NOMINAL IN
neck_length0.219 INCHES NOMINAL IN
thread_class2A A
head_diameter0.844 INCHES NOMINAL IN
thread_length0.750 INCHES NOMINAL IN
fastener_length0.750 INCHES NOMINAL IN
hardness_rating25.0 ROCKWELL C MINIMUM OVERALL
thread_directionRIGHT-HAND
surface_treatmentZINC OVERALL
NSN5306-01-592-1998
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: 90185A621 · 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
•
NECK LENGTH: 0.219 INCHES NOMINAL IN
•
HEAD HEIGHT: 0.208 INCHES NOMINAL IN
•
FASTENER LENGTH: 0.750 INCHES NOMINAL IN
•
THREAD LENGTH: 0.750 INCHES NOMINAL IN
•
HARDNESS RATING: 25.0 ROCKWELL C MINIMUM OVERALL
•
NOMINAL THREAD DIAMETER: 0.375 INCHES IN
•
HEAD STYLE: FLAT FILLISTER
•
THREAD DIRECTION: RIGHT-HAND
TECHNICAL CHARACTERISTICS
NECK LENGTH0.219 INCHES NOMINAL IN
HEAD HEIGHT0.208 INCHES NOMINAL IN
FASTENER LENGTH0.750 INCHES NOMINAL IN
THREAD LENGTH0.750 INCHES NOMINAL IN
HARDNESS RATING25.0 ROCKWELL C MINIMUM OVERALL
NOMINAL THREAD DIAMETER0.375 INCHES IN
HEAD STYLEFLAT FILLISTER
THREAD DIRECTIONRIGHT-HAND
NECK WIDTH0.388 INCHES NOMINAL IN
SURFACE TREATMENTZINC 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
Acquisition advice: Normally procured from the manufacturer (OEM)No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 90185A621?
90185A621 is a BOLT,SQUARE NECK.
What is the NSN for 90185A621?
90185A621 is cataloged in the U.S. Government catalog under NSN 5306-01-592-1998. 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.