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21C612 — BOLT,MACHINE

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

21C612: BOLT,MACHINE.

The BOLT,MACHINE is a the manufacturer industrial component. Key specifications include head_style: HEXAGON, head_height: 0.226 INCHES MINIMUM AND 0.243 INCHES MAXIMUM IN, thread_class: 2A A, thread_length: 0.564 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN, fastener_length: 0.720 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN, hardness_rating: 25.0 ROCKWELL C MINIMUM AND 34.0 ROCKWELL C MAXIMUM OVERALL. This part is cataloged in the U.S.

Government catalog under NSN 5306-01-197-4445, 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
21C612
NSN: 5306-01-197-4445
FSC: 5306 — Bolts
CAGE: 076M6 — AMZ ALABAMA INC. (USA)
SPECIFICATIONS
head_styleHEXAGON
head_height0.226 INCHES MINIMUM AND 0.243 INCHES MAXIMUM IN
thread_class2A A
thread_length0.564 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
fastener_length0.720 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
hardness_rating25.0 ROCKWELL C MINIMUM AND 34.0 ROCKWELL C MAXIMUM OVERALL
locking_featurePATCH THREADS
thread_directionRIGHT-HAND
features_providedFINISHED HEAD
width_between_flats0.551 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN
end_item_identificationARMORED COMBAT EARTHMOVER (M9);M9 ACE, COMBAT EXCAVATOR
nominal_thread_diameter0.375 INCHES IN
NSN5306-01-197-4445
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: 21C612 · 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
•
HEAD HEIGHT: 0.226 INCHES MINIMUM AND 0.243 INCHES MAXIMUM IN
•
FASTENER LENGTH: 0.720 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
•
THREAD LENGTH: 0.564 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
•
HARDNESS RATING: 25.0 ROCKWELL C MINIMUM AND 34.0 ROCKWELL C MAXIMUM OVERALL
•
MATERIAL DOCUMENT AND CLASSIFICATION: SAE J429 GR 5 ASSN STD ALL MATERIAL RESPONSES OVERALL
•
NOMINAL THREAD DIAMETER: 0.375 INCHES IN
•
FEATURES PROVIDED: FINISHED HEAD
•
HEAD STYLE: HEXAGON
TECHNICAL CHARACTERISTICS
HEAD HEIGHT0.226 INCHES MINIMUM AND 0.243 INCHES MAXIMUM IN
FASTENER LENGTH0.720 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
THREAD LENGTH0.564 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN
HARDNESS RATING25.0 ROCKWELL C MINIMUM AND 34.0 ROCKWELL C MAXIMUM OVERALL
MATERIAL DOCUMENT AND CLASSIFICATIONSAE J429 GR 5 ASSN STD ALL MATERIAL RESPONSES OVERALL
NOMINAL THREAD DIAMETER0.375 INCHES IN
FEATURES PROVIDEDFINISHED HEAD
HEAD STYLEHEXAGON
THREAD DIRECTIONRIGHT-HAND
WIDTH BETWEEN FLATS0.551 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN
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

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 21C612?
21C612 is a BOLT,MACHINE.
What is the NSN for 21C612?
21C612 is cataloged in the U.S. Government catalog under NSN 5306-01-197-4445. 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.