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SS-8478-12 — SCREW,SHOULDER

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

SS-8478-12: SCREW,SHOULDER.

The SCREW,SHOULDER is a the manufacturer industrial component. Key specifications include material: STEEL COMP 303 OVERALL, head_style: FLAT CHAMFER, head_height: 0.240 INCHES MINIMUM AND 0.260 INCHES MAXIMUM IN, thread_class: 3A A, head_diameter: 0.621 INCHES MINIMUM AND 0.629 INCHES MAXIMUM IN, thread_length: 0.495 INCHES MINIMUM AND 0.505 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 5305-01-522-6545, 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
SS-8478-12
NSN: 5305-01-522-6545
FSC: 5305 — Screws
CAGE: 0GCW4 — GLOBE ELECTRONIC HARDWARE, INC. (USA)
SPECIFICATIONS
materialSTEEL COMP 303 OVERALL
head_styleFLAT CHAMFER
head_height0.240 INCHES MINIMUM AND 0.260 INCHES MAXIMUM IN
thread_class3A A
head_diameter0.621 INCHES MINIMUM AND 0.629 INCHES MAXIMUM IN
thread_length0.495 INCHES MINIMUM AND 0.505 INCHES MAXIMUM IN
shoulder_shapeROUND FIRST SHOULDER
fastener_length1.125 INCHES NOMINAL IN
shoulder_length0.625 INCHES MINIMUM AND 0.627 INCHES MAXIMUM FIRST SHOULDER IN
thread_directionRIGHT-HAND
shoulder_diameter0.498 INCHES MINIMUM AND 0.499 INCHES MAXIMUM FIRST SHOULDER IN
surface_treatmentPASSIVATE OVERALL
NSN5305-01-522-6545
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: SS-8478-12 · 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: 0.240 INCHES MINIMUM AND 0.260 INCHES MAXIMUM IN
•
FASTENER LENGTH: 1.125 INCHES NOMINAL IN
•
SHOULDER LENGTH: 0.625 INCHES MINIMUM AND 0.627 INCHES MAXIMUM FIRST SHOULDER IN
•
SHOULDER DIAMETER: 0.498 INCHES MINIMUM AND 0.499 INCHES MAXIMUM FIRST SHOULDER IN
•
THREAD LENGTH: 0.495 INCHES MINIMUM AND 0.505 INCHES MAXIMUM IN
•
SHOULDER SHAPE: ROUND FIRST SHOULDER
•
NOMINAL THREAD DIAMETER: 0.375 INCHES IN
TECHNICAL CHARACTERISTICS
WIDTH ACROSS FLATS0.250 INCHES NOMINAL IN
HEAD HEIGHT0.240 INCHES MINIMUM AND 0.260 INCHES MAXIMUM IN
FASTENER LENGTH1.125 INCHES NOMINAL IN
SHOULDER LENGTH0.625 INCHES MINIMUM AND 0.627 INCHES MAXIMUM FIRST SHOULDER IN
SHOULDER DIAMETER0.498 INCHES MINIMUM AND 0.499 INCHES MAXIMUM FIRST SHOULDER IN
THREAD LENGTH0.495 INCHES MINIMUM AND 0.505 INCHES MAXIMUM IN
SHOULDER SHAPEROUND FIRST SHOULDER
NOMINAL THREAD DIAMETER0.375 INCHES IN
HEAD STYLEFLAT CHAMFER
THREAD DIRECTIONRIGHT-HAND
OTHER ITEMS IN FSC 5305 — Screws
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5305-00-000-0094 5305-00-000-1397 5305-00-000-2625 5305-00-000-3669 5305-00-000-3830 5305-00-000-3831
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 SS-8478-12?
SS-8478-12 is a SCREW,SHOULDER.
What is the NSN for SS-8478-12?
SS-8478-12 is cataloged in the U.S. Government catalog under NSN 5305-01-522-6545. 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.