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51B333-18 — SCREW,CLOSE TOLERANCE

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

51B333-18: SCREW,CLOSE TOLERANCE.

The SCREW,CLOSE TOLERANCE is a the manufacturer industrial component. Key specifications include head_style: FLAT COUNTERSUNK, grip_length: 1.115 INCHES MINIMUM AND 1.135 INCHES MAXIMUM IN, thread_class: 3A A, grip_diameter: 0.1885 INCHES MINIMUM AND 0.1895 INCHES MAXIMUM IN, head_diameter: 0.329 INCHES MINIMUM AND 0.385 INCHES MAXIMUM IN, thread_length: 0.250 INCHES MINIMUM AND 0.317 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 5305-00-809-1738, 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
51B333-18
NSN: 5305-00-809-1738
FSC: 5305 — Screws
CAGE: 06725 — SPS TECHNOLOGIES, LLC DBA AIR INDUSTRIES COMPANY DIV AIR INDUSTRIES COMPANY (USA)
SPECIFICATIONS
materialSTEEL COMP 4140 OR STEEL COMP 8740 OR STEEL COMP 4340 OR STEEL COMP E4340 OR STEEL COMP 8735 OR STEEL COMP 6150 OVERALL
head_styleFLAT COUNTERSUNK
grip_length1.115 INCHES MINIMUM AND 1.135 INCHES MAXIMUM IN
thread_class3A A
grip_diameter0.1885 INCHES MINIMUM AND 0.1895 INCHES MAXIMUM IN
head_diameter0.329 INCHES MINIMUM AND 0.385 INCHES MAXIMUM IN
thread_length0.250 INCHES MINIMUM AND 0.317 INCHES MAXIMUM IN
surface_finish32.0 MICROINCHES GRIP
fastener_length1.385 INCHES MINIMUM AND 1.432 INCHES MAXIMUM IN
thread_directionRIGHT-HAND
countersink_angle100.0 DEGREES NOMINAL
surface_treatmentCADMIUM AND CHROMATE OVERALL
NSN5305-00-809-1738
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: 51B333-18 · 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 FINISH: 32.0 MICROINCHES GRIP
•
FASTENER LENGTH: 1.385 INCHES MINIMUM AND 1.432 INCHES MAXIMUM IN
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: QQ-P-416 TY 2 CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
•
THREAD LENGTH: 0.250 INCHES MINIMUM AND 0.317 INCHES MAXIMUM IN
•
NOMINAL THREAD DIAMETER: 0.190 INCHES IN
•
HEAD STYLE: FLAT COUNTERSUNK
•
THREAD DIRECTION: RIGHT-HAND
•
GRIP LENGTH: 1.115 INCHES MINIMUM AND 1.135 INCHES MAXIMUM IN
TECHNICAL CHARACTERISTICS
SURFACE FINISH32.0 MICROINCHES GRIP
FASTENER LENGTH1.385 INCHES MINIMUM AND 1.432 INCHES MAXIMUM IN
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONQQ-P-416 TY 2 CL 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
THREAD LENGTH0.250 INCHES MINIMUM AND 0.317 INCHES MAXIMUM IN
NOMINAL THREAD DIAMETER0.190 INCHES IN
HEAD STYLEFLAT COUNTERSUNK
THREAD DIRECTIONRIGHT-HAND
GRIP LENGTH1.115 INCHES MINIMUM AND 1.135 INCHES MAXIMUM IN
GRIP DIAMETER0.1885 INCHES MINIMUM AND 0.1895 INCHES MAXIMUM IN
SURFACE TREATMENTCADMIUM AND CHROMATE OVERALL
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: Insurance item — stocked against contingency demandNo demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 51B333-18?
51B333-18 is a SCREW,CLOSE TOLERANCE.
What is the NSN for 51B333-18?
51B333-18 is cataloged in the U.S. Government catalog under NSN 5305-00-809-1738. 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.