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GS520U5 — STUD ASSEMBLY,TURNLOCK FASTENER

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

GS520U5: STUD ASSEMBLY,TURNLOCK FASTENER.

STUD ASSEMBLY,TURNLOCK FASTENER. Key specifications include diameter: 0.373 INCHES MINIMUM AND 0.383 INCHES MAXIMUM IN, material: STEEL COMP 4037 STUD, eyelet_length: 0.080 INCHES MINIMUM AND 0.100 INCHES MAXIMUM IN, stud_diameter: 0.212 INCHES MINIMUM AND 0.215 INCHES MAXIMUM IN, stud_head_height: 0.285 INCHES NOMINAL IN, surface_treatment: CADMIUM AND CHROMATE STUD. This part is cataloged in the U.S.

Government catalog under NSN 5325-01-516-3256, 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
GS520U5
NSN: 5325-01-516-3256
FSC: 5325 — Fastening Devices
CAGE: 26512 — NORTHROP GRUMMAN SYSTEMS CORPORATION (USA)
SPECIFICATIONS
diameter0.373 INCHES MINIMUM AND 0.383 INCHES MAXIMUM IN
materialSTEEL COMP 4037 STUD
eyelet_length0.080 INCHES MINIMUM AND 0.100 INCHES MAXIMUM IN
stud_diameter0.212 INCHES MINIMUM AND 0.215 INCHES MAXIMUM IN
stud_head_height0.285 INCHES NOMINAL IN
surface_treatmentCADMIUM AND CHROMATE STUD
stud_assembly_styleSTUD ASSEMBLY
eyelet_outside_diameter0.373 INCHES MINIMUM AND 0.383 INCHES MAXIMUM IN
turnlock_stud_head_styleFLAT FILLISTER
material_accommodated_thickness0.070 INCHES MINIMUM AND 0.079 INCHES MAXIMUM IN
material_document_and_classificationAMS 6300 ASSN STD SINGLE MATERIAL RESPONSE STUD
surface_treatment_document_and_classificationQQ-P-416, TYPE 2, CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE STUD
NSN5325-01-516-3256
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: GS520U5 · 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
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: QQ-P-416, TYPE 2, CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE STUD
•
EYELET OUTSIDE DIAMETER: 0.373 INCHES MINIMUM AND 0.383 INCHES MAXIMUM IN
•
MATERIAL ACCOMMODATED THICKNESS: 0.070 INCHES MINIMUM AND 0.079 INCHES MAXIMUM IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 6300 ASSN STD SINGLE MATERIAL RESPONSE STUD
•
DIAMETER: 0.373 INCHES MINIMUM AND 0.383 INCHES MAXIMUM IN
•
STUD HEAD HEIGHT: 0.285 INCHES NOMINAL IN
•
DISTANCE FROM ENGAGING MEMBER TO LARGEST BEARING SURFACE OF HEAD: 0.540 INCHES NOMINAL IN
•
TURNLOCK STUD HEAD STYLE: FLAT FILLISTER
TECHNICAL CHARACTERISTICS
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONQQ-P-416, TYPE 2, CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE STUD
EYELET OUTSIDE DIAMETER0.373 INCHES MINIMUM AND 0.383 INCHES MAXIMUM IN
MATERIAL ACCOMMODATED THICKNESS0.070 INCHES MINIMUM AND 0.079 INCHES MAXIMUM IN
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 6300 ASSN STD SINGLE MATERIAL RESPONSE STUD
DIAMETER0.373 INCHES MINIMUM AND 0.383 INCHES MAXIMUM IN
STUD HEAD HEIGHT0.285 INCHES NOMINAL IN
DISTANCE FROM ENGAGING MEMBER TO LARGEST BEARING SURFACE OF HEAD0.540 INCHES NOMINAL IN
TURNLOCK STUD HEAD STYLEFLAT FILLISTER
SURFACE TREATMENTCADMIUM AND CHROMATE STUD
MATERIALSTEEL COMP 4037 STUD
OTHER ITEMS IN FSC 5325 — Fastening Devices
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5325-00-000-1884 5325-00-000-9988 5325-00-001-1567 5325-00-001-2043 5325-00-001-3842 5325-00-001-3858 5325-00-001-3871 5325-00-001-4317
SUBSTITUTES & CROSS-REFERENCES 1
PFSC35-39A-SEBReference document
Same NSN cross-reference
Reference document — Secondary reference
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 GS520U5?
GS520U5 is a STUD ASSEMBLY,TURNLOCK FASTENER.
What parts can replace GS520U5?
There is 1 known substitute for GS520U5: PFSC35-39A-SEB. Substitute compatibility should be verified for your specific system.
What is the NSN for GS520U5?
GS520U5 is cataloged in the U.S. Government catalog under NSN 5325-01-516-3256. 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.