Part Number
Hexagon Castellated Plain Nut · AN (Air Force-Navy) · NSN 5310-00-268-6075
| Part number | AN310C9 |
|---|---|
| Specification family | AN (Air Force-Navy) |
| Item name | Hexagon Castellated Plain Nut |
| Alternate references | AN310C9-MILN6034; MILN6034 |
| Unit of issue | EA |
| Cross-referenced NSN | 5310-00-268-6075 |
| Federal Supply Class (FSC) | 5310 — Nuts and Washers |
| Unit price (USD) | $3.51 |
| Country of origin | Türkiye (Turkey) |
| Lead time | Within 90 days of order |
| Minimum order | May apply — confirm on quote |
| Documentation | Source documentation provided on all orders |
Characteristics decoded from the federal cataloging record for this hexagon castellated plain nut. Confirm controlling dimensions against your drawing or standard sheet before ordering.
| Material | Steel Corrosion Resisting Overall |
|---|---|
| Surface Treatment | Passivate Overall |
| Thread Class | 3B |
| Thread Quantity Per Inch | 18 |
Internally threaded fasteners (hex nuts, lock nuts, castle nuts, wing nuts, self-locking nuts) and washers (flat, lock, spring, and special washers) used to distribute load and secure threaded assemblies.
Reading the part number. AN310C9 breaks down as AN310 — the Air Force-Navy design standard that fixes the part's design — plus the dash/suffix code C9, which selects the exact size, material, or finish variant from the tables on that standard. Two parts sharing the AN310 base are the same design in different variants.
Price in context. Across the 1,177 items we currently stock in FSC 5310 (Nuts and Washers), published unit prices run from $0.12 to $68,673.00. At $3.51, this item sits well below the class median of $8.76 — commodity hardware usually bought in volume.
Who orders AN310C9. Aircraft owners and MRO shops replacing standard hardware, machine shops and OEMs filling a bill of materials, and government contractors sourcing against NSN 5310-00-268-6075. You can order by part number or by stock number — it is the same item, the same published price, and the same quote form.
Applicable standards. ASME B18.2.2 / B18.16, B18.21 / B18.22, NASM/MS series; steel, stainless, and self-locking (nylon-insert and all-metal) designs.
Need this part modified, or a similar part made to your print? See our U.S.-based CNC machining services and aerospace machining capability.
Country of origin: Türkiye (Turkey) — a DFARS qualifying country. Türkiye is a NATO ally with a reciprocal defense procurement agreement with the U.S. Department of Defense, making it a qualifying country under DFARS 225.003. On DoD and DLA solicitations, qualifying-country end products are evaluated without Buy American price penalties — they compete on par with domestic product — and DoD trade-agreements clauses (DFARS 252.225-7021) expressly accept qualifying-country end products.
Dollar thresholds. The Trade Agreements Act only applies to supply contracts at or above $174,000 (the WTO GPA threshold effective March 2026); below that — where the vast majority of hardware buys fall — the TAA does not apply at all. The main exclusion is civilian-agency solicitations at or above that threshold that restrict award to TAA designated-country products (Türkiye is not TAA-designated). Buyers are responsible for confirming the origin requirements of their specific solicitation.
Full country-of-origin and source documentation is provided with every order. Fulfillment within 90 days of order. Minimum order may apply.
Items are supplied as stock mil-spec / commercial hardware with source documentation and country-of-origin paperwork on every order. Parts are not supplied with an FAA Form 8130-3 airworthiness tag unless expressly stated on the quote. Buyers installing hardware on certificated aircraft are responsible for acceptance under their own maintenance program, repair station procedures, or owner/operator authority.
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