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MS9581-09 — WASHER,KEY

✓ Government record, cited
— · NUT WASHER
PRODUCT OVERVIEW

MS9581-09: WASHER,KEY.

The WASHER,KEY is a the manufacturer industrial component. Key specifications include material: STEEL COMP 321 OVERALL, hole_diameter: 0.190 INCHES NOMINAL IN, outside_diameter: 0.195 INCHES MINIMUM AND 0.200 INCHES MAXIMUM IN, style_designator: 90 DEGREE LOCKING KEY, material_thickness: 0.019 INCHES MINIMUM AND 0.025 INCHES MAXIMUM IN, external_prebent_key_angle: 15.0 DEGREES NOMINAL. This part is cataloged in the U.S.

Government catalog under NSN 5310-00-121-8012, 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
MS9581-09
NSN: 5310-00-121-8012
FSC: 5310 — Nuts and Washers
CAGE: 0U583 — SAE INTERNATIONAL DBA SAE INTERNATIONAL (USA)
SPECIFICATIONS
materialSTEEL COMP 321 OVERALL
hole_diameter0.190 INCHES NOMINAL IN
outside_diameter0.195 INCHES MINIMUM AND 0.200 INCHES MAXIMUM IN
style_designator90 DEGREE LOCKING KEY
material_thickness0.019 INCHES MINIMUM AND 0.025 INCHES MAXIMUM IN
external_prebent_key_angle15.0 DEGREES NOMINAL
external_prebent_key_width0.110 INCHES MINIMUM AND 0.115 INCHES MAXIMUM IN
external_tapered_key_width0.200 INCHES MINIMUM AND 0.210 INCHES MAXIMUM IN
angle_between_external_keys58.0 DEGREES MINIMUM AND 62.0 DEGREES MAXIMUM
external_prebent_key_length0.095 INCHES MINIMUM AND 0.105 INCHES MAXIMUM IN
material_document_and_classificationAMS 5510 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
distance_from_centerline_to_inside_of_prebent_key0.221 INCHES MINIMUM AND 0.231 INCHES MAXIMUM IN
NSN5310-00-121-8012
COMPONENT DIAGRAM
NUT & WASHER — GRADE MATCHING REQUIRED Hex NUT CROSS-SECTION WASHER OD: — SIZE: — MATERIAL: — PN: MS9581-09 · 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
•
DISTANCE FROM CENTERLINE TO INSIDE OF PREBENT KEY: 0.221 INCHES MINIMUM AND 0.231 INCHES MAXIMUM IN
•
EXTERNAL PREBENT KEY LENGTH: 0.095 INCHES MINIMUM AND 0.105 INCHES MAXIMUM IN
•
STYLE DESIGNATOR: 90 DEGREE LOCKING KEY
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 5510 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
•
OUTSIDE DIAMETER: 0.195 INCHES MINIMUM AND 0.200 INCHES MAXIMUM IN
•
EXTERNAL TAPERED KEY WIDTH: 0.200 INCHES MINIMUM AND 0.210 INCHES MAXIMUM IN
•
MATERIAL THICKNESS: 0.019 INCHES MINIMUM AND 0.025 INCHES MAXIMUM IN
•
EXTERNAL PREBENT KEY ANGLE: 15.0 DEGREES NOMINAL
TECHNICAL CHARACTERISTICS
DISTANCE FROM CENTERLINE TO INSIDE OF PREBENT KEY0.221 INCHES MINIMUM AND 0.231 INCHES MAXIMUM IN
EXTERNAL PREBENT KEY LENGTH0.095 INCHES MINIMUM AND 0.105 INCHES MAXIMUM IN
STYLE DESIGNATOR90 DEGREE LOCKING KEY
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 5510 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
OUTSIDE DIAMETER0.195 INCHES MINIMUM AND 0.200 INCHES MAXIMUM IN
EXTERNAL TAPERED KEY WIDTH0.200 INCHES MINIMUM AND 0.210 INCHES MAXIMUM IN
MATERIAL THICKNESS0.019 INCHES MINIMUM AND 0.025 INCHES MAXIMUM IN
EXTERNAL PREBENT KEY ANGLE15.0 DEGREES NOMINAL
EXTERNAL PREBENT KEY WIDTH0.110 INCHES MINIMUM AND 0.115 INCHES MAXIMUM IN
MATERIALSTEEL COMP 321 OVERALL
OTHER ITEMS IN FSC 5310 — Nuts and Washers
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5310-00-000-0040 5310-00-000-0077 5310-00-000-0079 5310-00-000-1146 5310-00-000-3815 5310-00-000-4532 5310-00-000-4540
SUBSTITUTES & CROSS-REFERENCES 1
SAE AS9581Reference document
Same NSN cross-reference
Reference document — Secondary reference
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 MS9581-09?
MS9581-09 is a WASHER,KEY.
What parts can replace MS9581-09?
There is 1 known substitute for MS9581-09: SAE AS9581. Substitute compatibility should be verified for your specific system.
What is the NSN for MS9581-09?
MS9581-09 is cataloged in the U.S. Government catalog under NSN 5310-00-121-8012. 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.