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MS21045-4

Military Standard Locking Hexagon Nut Self

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Description

Nut

Specifications

Bearing Surface Finish 125.0 microinches
Bearing Surface Type Chamfered or washer faced
Countersink Angle 88.0 degrees nut
Features Regular Height
Industry Standards/Certification MS21045
Locking Feature Prevailing torque all metal design
Lubricant Non-Dry Lubricant
Lubrication Soluble lubricant
Material Steel
Maximum Dimension A 0.328 in
Maximum Dimension B 0.439 in
Minimum Dimension A 0.240 in
Minimum Dimension B 0.430 in
Minimum Dimension C 0.482 in
Minimum Dimension F 0.116 in
NIIN 00-061-7325
NSN 5310-00-061-7325
Nut Height Between 0.240 inches and 0.328 inches
Nut Style Hexagon
Service Temperature 450 ºF
Surface Treatment Cadmium
Surface Treatment Specification Cl 3 federal specification single treatment response type 2 qq-p-416
Temperature Rating 450.0 degrees fahrenheit
Thread Class 3b
Thread Direction Right-hand
Thread MIL-S-8879 0.2500-28
Thread Qty 28
Thread Qty Per Inch (tpi) 28
Thread Series Unjf (fine thread with external controlled root radius)
Thread Size 0.250, 1/4-28
Type Self-Locking Nut
Weight 0.0073 lb
Width Across Flats Between 0.430 inches and 0.439 inches

Other sizes

Parts that share this base number, ordered by size. Always verify the full specification before substituting.

Cross-reference

Interchangeable

Parts that share a National Stock Number or are listed as an alternate for MS21045-4 — functionally equivalent.

Similar parts

Parts with matching key dimensions — often from a different standards family. Candidates for comparison only; verify the full specification before substituting.

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Catalog data updated 2026-07-05. Report a data error