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NAS1221-4-12 — SCREW,MACHINE

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

NAS1221-4-12: SCREW,MACHINE.

The SCREW,MACHINE is a the manufacturer industrial component. Key specifications include head_style: FLAT COUNTERSUNK, thread_class: 3A A, head_diameter: 0.461 INCHES MINIMUM AND 0.507 INCHES MAXIMUM IN, thread_length: 0.400 INCHES MINIMUM AND 0.467 INCHES MAXIMUM IN, screw_material: STEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 8740, fastener_length: 1.160 INCHES MINIMUM AND 1.207 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 5305-00-059-9564, 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
NAS1221-4-12
NSN: 5305-00-059-9564
FSC: 5305 — Screws
CAGE: 17446 — HUCK INTERNATIONAL, INC (USA)
SPECIFICATIONS
head_styleFLAT COUNTERSUNK
thread_class3A A
head_diameter0.461 INCHES MINIMUM AND 0.507 INCHES MAXIMUM IN
thread_length0.400 INCHES MINIMUM AND 0.467 INCHES MAXIMUM IN
screw_materialSTEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 8740
fastener_length1.160 INCHES MINIMUM AND 1.207 INCHES MAXIMUM IN
hardness_rating36.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM
thread_directionRIGHT-HAND
countersink_angle99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM
internal_drive_styleHIGH-TORQUE
nominal_thread_diameter0.250 INCHES IN
screw_surface_treatmentCADMIUM
NSN5305-00-059-9564
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: NAS1221-4-12 · 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
•
SCREW SURFACE TREATMENT: CADMIUM
•
FASTENER LENGTH: 1.160 INCHES MINIMUM AND 1.207 INCHES MAXIMUM IN
•
SCREW MATERIAL DOCUMENT AND CLASSIFICATION: MIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6059 MIL SPEC 3RD MATERIAL RESPONSE
•
THREAD LENGTH: 0.400 INCHES MINIMUM AND 0.467 INCHES MAXIMUM IN
•
HARDNESS RATING: 36.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM
•
NOMINAL THREAD DIAMETER: 0.250 INCHES IN
•
HEAD STYLE: FLAT COUNTERSUNK
•
THREAD DIRECTION: RIGHT-HAND
TECHNICAL CHARACTERISTICS
SCREW SURFACE TREATMENTCADMIUM
FASTENER LENGTH1.160 INCHES MINIMUM AND 1.207 INCHES MAXIMUM IN
SCREW MATERIAL DOCUMENT AND CLASSIFICATIONMIL-S-5626 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-5000 MIL SPEC 2ND MATERIAL RESPONSE OR MIL-S-6059 MIL SPEC 3RD MATERIAL RESPONSE
THREAD LENGTH0.400 INCHES MINIMUM AND 0.467 INCHES MAXIMUM IN
HARDNESS RATING36.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM
NOMINAL THREAD DIAMETER0.250 INCHES IN
HEAD STYLEFLAT COUNTERSUNK
THREAD DIRECTIONRIGHT-HAND
SPECIFICATION/STANDARD DATA80205-NAS1221 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD
SCREW MATERIALSTEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 8740
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 NAS1221-4-12?
NAS1221-4-12 is a SCREW,MACHINE.
What is the NSN for NAS1221-4-12?
NAS1221-4-12 is cataloged in the U.S. Government catalog under NSN 5305-00-059-9564. 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.