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S371-4D27 — BOLT,CLOSE TOLERANCE

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

S371-4D27: BOLT,CLOSE TOLERANCE.

The BOLT,CLOSE TOLERANCE is a the manufacturer industrial component. Key specifications include material: STEEL COMP XM-13 OVERALL, head_style: DOUBLE HEXAGON W/HOLE, grip_length: 1.678 INCHES MINIMUM AND 1.698 INCHES MAXIMUM IN, head_height: 0.290 INCHES MINIMUM AND 0.310 INCHES MAXIMUM IN, thread_class: 3A A, grip_diameter: 0.2490 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 5306-01-030-4657, 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
S371-4D27
NSN: 5306-01-030-4657
FSC: 5306 — Bolts
CAGE: 17446 — HUCK INTERNATIONAL, INC (USA)
SPECIFICATIONS
materialSTEEL COMP XM-13 OVERALL
head_styleDOUBLE HEXAGON W/HOLE
grip_length1.678 INCHES MINIMUM AND 1.698 INCHES MAXIMUM IN
head_height0.290 INCHES MINIMUM AND 0.310 INCHES MAXIMUM IN
thread_class3A A
grip_diameter0.2490 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN
thread_length0.443 INCHES MINIMUM AND 0.493 INCHES MAXIMUM IN
fastener_length2.141 INCHES MINIMUM AND 2.171 INCHES MAXIMUM IN
thread_directionRIGHT-HAND
surface_treatmentPASSIVATE OVERALL
width_between_flats0.304 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN
nominal_thread_diameter0.250 INCHES IN
NSN5306-01-030-4657
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: S371-4D27 · 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
•
EXTENDED WASHER THICKNESS: 0.059 INCHES MINIMUM AND 0.079 INCHES MAXIMUM IN
•
HEAD HEIGHT: 0.290 INCHES MINIMUM AND 0.310 INCHES MAXIMUM IN
•
FASTENER LENGTH: 2.141 INCHES MINIMUM AND 2.171 INCHES MAXIMUM IN
•
EXTENDED WASHER DIAMETER: 0.428 INCHES MINIMUM AND 0.438 INCHES MAXIMUM IN
•
THREAD LENGTH: 0.443 INCHES MINIMUM AND 0.493 INCHES MAXIMUM IN
•
SHANK UNTHREADED HOLE DIAMETER: 0.076 INCHES MINIMUM AND 0.081 INCHES MAXIMUM FIRST HOLE IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 5629 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
•
NOMINAL THREAD DIAMETER: 0.250 INCHES IN
TECHNICAL CHARACTERISTICS
EXTENDED WASHER THICKNESS0.059 INCHES MINIMUM AND 0.079 INCHES MAXIMUM IN
HEAD HEIGHT0.290 INCHES MINIMUM AND 0.310 INCHES MAXIMUM IN
FASTENER LENGTH2.141 INCHES MINIMUM AND 2.171 INCHES MAXIMUM IN
EXTENDED WASHER DIAMETER0.428 INCHES MINIMUM AND 0.438 INCHES MAXIMUM IN
THREAD LENGTH0.443 INCHES MINIMUM AND 0.493 INCHES MAXIMUM IN
SHANK UNTHREADED HOLE DIAMETER0.076 INCHES MINIMUM AND 0.081 INCHES MAXIMUM FIRST HOLE IN
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 5629 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
NOMINAL THREAD DIAMETER0.250 INCHES IN
HEAD STYLEDOUBLE HEXAGON W/HOLE
THREAD DIRECTIONRIGHT-HAND
OTHER ITEMS IN FSC 5306 — Bolts
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5306-00-001-1276 5306-00-001-1949 5306-00-001-1988 5306-00-001-1989 5306-00-001-1990 5306-00-001-1991 5306-00-001-1993 5306-00-001-2017
SUBSTITUTES & CROSS-REFERENCES 7
BM3326-4D27Reference document
Same NSN cross-reference
Reference document — Secondary reference
VAL23033-4D27Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
74328-4D27Reference document
Same NSN cross-reference
Reference document — Secondary reference
SLB253-4D27Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
ST3M571-4D27Reference document
Same NSN cross-reference
Reference document — Secondary reference
S11-1059-4D27Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
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 S371-4D27?
S371-4D27 is a BOLT,CLOSE TOLERANCE.
What parts can replace S371-4D27?
There are 7 known substitutes for S371-4D27: BM3326-4D27, VAL23033-4D27, 74328-4D27 and 4 more. Substitute compatibility should be verified for your specific system.
What is the NSN for S371-4D27?
S371-4D27 is cataloged in the U.S. Government catalog under NSN 5306-01-030-4657. 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.