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BCKX1EF1 — SCREW,MACHINE

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

BCKX1EF1: SCREW,MACHINE.

The SCREW,MACHINE is a the manufacturer industrial component. Key specifications include head_style: FLAT COUNTERSUNK, thread_class: 2A A, head_diameter: 0.257 INCHES MINIMUM AND 0.279 INCHES MAXIMUM IN, thread_length: 0.406 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN, fastener_length: 0.406 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN, thread_direction: RIGHT-HAND. This part is cataloged in the U.S.

Government catalog under NSN 5305-00-013-3427, 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
BCKX1EF1
NSN: 5305-00-013-3427
FSC: 5305 — Screws
CAGE: 00000
SPECIFICATIONS
head_styleFLAT COUNTERSUNK
thread_class2A A
head_diameter0.257 INCHES MINIMUM AND 0.279 INCHES MAXIMUM IN
thread_length0.406 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN
fastener_length0.406 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN
thread_directionRIGHT-HAND
countersink_angle80.0 DEGREES MINIMUM AND 82.0 DEGREES MAXIMUM
internal_drive_styleSLOT
nominal_thread_diameter0.138 INCHES IN
screw_surface_treatmentCADMIUM
minimum_tensile_strength60000 POUNDS PER SQUARE INCH LBS
thread_quantity_per_inch32
NSN5305-00-013-3427
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: BCKX1EF1 · 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: 0.406 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN
•
SCREW MATERIAL DOCUMENT AND CLASSIFICATION: QQ-S-634 FED SPEC ALL MATERIAL RESPONSES
•
THREAD LENGTH: 0.406 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN
•
NOMINAL THREAD DIAMETER: 0.138 INCHES IN
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HEAD STYLE: FLAT COUNTERSUNK
•
THREAD DIRECTION: RIGHT-HAND
•
NONDEFINITIVE SPEC/STD DATA: I TYPE AND 2S STYLE
TECHNICAL CHARACTERISTICS
SCREW SURFACE TREATMENTCADMIUM
FASTENER LENGTH0.406 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN
SCREW MATERIAL DOCUMENT AND CLASSIFICATIONQQ-S-634 FED SPEC ALL MATERIAL RESPONSES
THREAD LENGTH0.406 INCHES MINIMUM AND 0.437 INCHES MAXIMUM IN
NOMINAL THREAD DIAMETER0.138 INCHES IN
HEAD STYLEFLAT COUNTERSUNK
THREAD DIRECTIONRIGHT-HAND
NONDEFINITIVE SPEC/STD DATAI TYPE AND 2S STYLE
SCREW MATERIALSTEEL COMP 1010 OR STEEL COMP 1015 OR STEEL COMP 1016 OR STEEL COMP 1018 OR STEEL COMP 1019 OR STEEL COMP 1020 OR STEEL COMP 1022 OR STEEL COMP 1025 OR STEEL COMP 1026 OR STEEL COMP 1035 OR STEEL COMP 1040 OR STEEL COMP 1042 OR STEEL COMP 1045 OR STEEL COMP 1046 OR STEEL COMP 1548 OR STEEL COMP 1049 OR STEEL COMP 1050
MINIMUM TENSILE STRENGTH60000 POUNDS PER SQUARE INCH LBS
SUBSTITUTES & CROSS-REFERENCES 3
133427Reference document
Same NSN cross-reference
Reference document — Secondary reference
MS35241-36Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
12Z1013-203Reference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is BCKX1EF1?
BCKX1EF1 is a SCREW,MACHINE.
What parts can replace BCKX1EF1?
There are 3 known substitutes for BCKX1EF1: 133427, MS35241-36, 12Z1013-203. Substitute compatibility should be verified for your specific system.
What is the NSN for BCKX1EF1?
BCKX1EF1 is cataloged in the U.S. Government catalog under NSN 5305-00-013-3427. 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.