Aerospace Nuts
Roughly 4,400 nuts spanning self-locking, castellated, plain hex, and shear styles. MS21042 and MS21044 self-locking nuts, AN310 and AN320 castellated nuts, and their companions in CRES and cadmium-plated alloy steel, ready to order with full AS9120 traceability.
Aerospace Nut Types
From MS21042 all-metal locknuts to AN310 castle nuts, we cover the nut families called out on commercial and military drawings in alloy steel and CRES.
All-Metal Self-Locking Nuts
MS21042 reduced-hex, reduced-height nuts develop prevailing torque through deformed threads, with no nylon element. Typically rated to about 450 degrees F, they are the compact, high-strength choice across current airframe structure.
Nylon-Insert Self-Locking Nuts
MS21044 nuts carry a nylon locking collar, the classic elastic stop nut design. Typically limited to about 250 degrees F, they serve general airframe and equipment joints where temperatures stay moderate.
Castellated Nuts
AN310 castle nuts are slotted for cotter pins and pair with drilled-shank bolts on clevis and rotating joints. AN320 is the thinner shear castellated style for joints loaded in shear rather than tension.
Plain Hex & Shear Nuts
Plain nuts such as AN315, check nuts such as AN316 for jam-locking, and thin shear nuts for positions where the bolt carries load across the joint. Each style is tied to a specific safetying method on the drawing.
Nut Materials & Finishes
Cadmium-Plated Alloy Steel
High-strength nuts matched to plated alloy steel bolts, the standard pairing across legacy and current structure. Cadmium plate provides corrosion protection and consistent torque behavior.
CRES & A286
Corrosion-resistant and precipitation-hardened stainless nuts for engine, nacelle, and other hot or corrosive zones where plated alloy steel is unsuitable, typically paired with CRES bolts.
Locking Elements
All-metal deformed-thread locking for higher temperatures versus nylon inserts for moderate zones. The temperature limits, typically about 450 degrees F and 250 degrees F respectively, drive which family the drawing calls out.
Finishes
Cadmium plate, dry-film lubricant, and passivation, matched to the mating bolt finish. Silver-plated threads appear on some high-temperature CRES nuts. Order the exact dash number and finish from your drawing.
How to Order Aerospace Nuts
Search by Part Number
Enter your MS21042, MS21044, AN310, AN315, or AN320 nut part number, including the dash number for thread size and material, and review the available options.
Get a Fast Online Quote
Add the quantities you need to your quote. Compare options sourced from our approved suppliers on price, lead time, and minimum order quantity.
Order with Confidence
Check out securely online. Every shipment includes certificates of conformance backed by our AS9120 Rev B quality management system.
Your Distribution Partner for Aircraft Nuts
With roughly 4,400 nut line items in the Instaparts catalog of 266,000+ aerospace parts, we cover the half of the bolted joint that usually gets less attention. A joint is only as good as the nut that closes it: the nut carries the preload, provides the locking feature, and determines the safetying method. The drawing callout defines the standard, material, and finish, and substituting "a nut that fits" is never acceptable in aerospace. The part must arrive with documentation proving it is what it claims to be.
The specification landscape splits along locking method and temperature. MS21042 reduced-hex all-metal locknuts use deformed threads and are typically rated to about 450 degrees F, making them the compact choice on current structure. MS21044 nylon-insert nuts serve moderate-temperature joints, typically to about 250 degrees F. Castellated AN310 nuts pair with drilled bolts and cotter pins on clevis and rotating joints, with the thinner AN320 covering shear-loaded positions. Plain AN315 nuts and AN316 check nuts round out the family where the drawing pairs them with a separate locking device. Instaparts catalogs all of these families, so you can search and quote by exact part number.
Every nut we supply moves through our AS9120 Rev B certified quality management system. Instaparts, a division of RFQ2Go, Inc. based in Toronto, Canada, sources exclusively from approved suppliers and applies counterfeit-prevention controls aligned with AS6081, critical for threaded hardware, which remains one of the most frequently counterfeited commodity groups in aerospace. Shipments include certificates of conformance, and lot traceability is maintained from receipt through delivery.
Nuts never travel alone. The same drawings call out aerospace bolts for the mating fastener, aerospace washers to seat the joint, and aerospace nutplates where the nut must be anchored to blind structure. If your requirement covers multiple categories or a long bill of materials, send it through our quote page and our team will price the complete package.
Aerospace Nut FAQs
What is the difference between MS21042 and MS21044 nuts?
MS21042 is an all-metal self-locking nut with a reduced hexagon and reduced height; its locking action comes from deformed threads, and it is typically rated to about 450 degrees F. MS21044 uses a nylon locking insert and is typically limited to about 250 degrees F. The drawing callout determines which is required; temperature and material rules make them non-interchangeable.
When are castellated nuts such as AN310 or AN320 required?
Castellated nuts are slotted so a cotter pin can pass through the nut and a drilled bolt shank, providing positive mechanical safetying on clevis pins, control connections, and rotating joints. AN310 is the standard tension style, while the thinner AN320 is intended for joints loaded in shear only.
Can self-locking nuts be reused?
Reuse practice is governed by the applicable maintenance manual. A self-locking nut that no longer develops its minimum prevailing torque must be replaced, and many operators simply replace self-locking nuts at every removal. When in doubt, install new hardware with full documentation.
Do you supply OEM and hard-to-find nut part numbers?
Yes. Our catalog of 266,000+ parts includes the MS, AN, and NAS nut families along with OEM-proprietary callouts. Search by the exact part number, including the dash number for thread size and material, and request a fast online quote.
What documentation comes with your nuts?
Instaparts operates an AS9120 Rev B certified quality management system. Orders ship with certificates of conformance, lot traceability is maintained back to our approved suppliers, and counterfeit-prevention controls aligned with AS6081 are applied to every fastener purchase.
Need Aerospace Nuts?
Browse the catalog by MS21042, MS21044, AN310, or AN320 part number and get a fast online quote with full AS9120 traceability.
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