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21187-1 — NUT,PLAIN,HEXAGON

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

21187-1: NUT,PLAIN,HEXAGON.

The NUT,PLAIN,HEXAGON is a the manufacturer industrial component. Key specifications include material: STEEL CORROSION RESISTING OVERALL, nut_style: HEXAGON, nut_height: 0.313 INCHES NOMINAL IN, thread_class: 3B, thread_series: UNF, thread_direction: RIGHT-HAND. This part is cataloged in the U.S.

Government catalog under NSN 5310-00-080-1788, 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
21187-1
NSN: 5310-00-080-1788
NIINs: 000801788, 012155147
FSC: 5310 — Nuts and Washers
CAGE: 21439 — CURTISS-WRIGHT FLOW CONTROL SERVICE, LLC DBA ENGINEERED ARRESTING SYSTEMS - ESCO DIV CW FLOW CONTROL SVC LLC DBA (USA)
SPECIFICATIONS
materialSTEEL CORROSION RESISTING OVERALL
nut_styleHEXAGON
nut_height0.313 INCHES NOMINAL IN
thread_class3B
thread_seriesUNF
thread_directionRIGHT-HAND
surface_treatmentPASSIVATE OVERALL
width_across_flats0.986 INCHES MINIMUM AND 1.002 INCHES MAXIMUM IN
nominal_thread_size0.625 INCHES IN
bearing_surface_typeCHAMFERED
drilled_hole_diameter0.070 INCHES NOMINAL IN
hole_type_and_quantity3 DRILLED
NSN5310-00-080-1788
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: 21187-1 · OEM ⚠ VERIFY BEFORE ORDERING Grade matters for torque spec — don't mix grades. A Grade 5 nut on a Grade 8 bolt weakens the joint. Lock nuts, wing nuts, and castle nuts are NOT interchangeable with standard hex ✓ BROKER TIP Match nut to bolt thread class and material. Stainless bolt + zinc nut = galvanic corrosion. Always verify finish matches (plain, zinc, hot-dip galvanized) PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
WIDTH ACROSS FLATS: 0.986 INCHES MINIMUM AND 1.002 INCHES MAXIMUM IN
•
THREAD SERIES: UNF
•
HOLE CONFIGURATION STYLE: CONFIGURATION B
•
THREAD DIRECTION: RIGHT-HAND
•
NOMINAL THREAD SIZE: 0.625 INCHES IN
•
NUT HEIGHT: 0.313 INCHES NOMINAL IN
•
DRILLED HOLE DIAMETER: 0.070 INCHES NOMINAL IN
•
SURFACE TREATMENT: PASSIVATE OVERALL
TECHNICAL CHARACTERISTICS
WIDTH ACROSS FLATS0.986 INCHES MINIMUM AND 1.002 INCHES MAXIMUM IN
THREAD SERIESUNF
HOLE CONFIGURATION STYLECONFIGURATION B
THREAD DIRECTIONRIGHT-HAND
NOMINAL THREAD SIZE0.625 INCHES IN
NUT HEIGHT0.313 INCHES NOMINAL IN
DRILLED HOLE DIAMETER0.070 INCHES NOMINAL IN
SURFACE TREATMENTPASSIVATE OVERALL
NUT STYLEHEXAGON
THREAD CLASS3B
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 21187-1?
21187-1 is a NUT,PLAIN,HEXAGON.
What is the NSN for 21187-1?
21187-1 is cataloged in the U.S. Government catalog under NSN 5310-00-080-1788. 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.