NAS1221-3-6P

Externally threaded fasteners designed to be turned to assemble or adjust parts, including machine screws, cap screws, socket-head cap screws, set screws, self-tapping and thread-forming screws. This is the largest single class in the U.S. supply system and covers a vast range of thread sizes, drive types, head styles, and materials.

Reading the part number. NAS1221-3-6P breaks down as NAS1221 — the National Aerospace Standard that fixes the part's design — plus the dash/suffix code 3-6P, which selects the exact size, material, or finish variant from the tables on that standard. Two parts sharing the NAS1221 base are the same design in different variants.

Price in context. Across the 2,357 items we currently stock in FSC 5305 (Screws), published unit prices run from $0.03 to $14,752.17. At $17.52, this item sits above the class median of $10.52.

Stock activity. This item has appeared once in our supplier stock feed, most recently listed 2026-08-12, with a lot quantity of 58 units. Listing activity is a practical signal of ongoing availability; confirm current stock and firm pricing on your quote.

Who orders NAS1221-3-6P. Aircraft owners and MRO shops replacing standard hardware, machine shops and OEMs filling a bill of materials, and government contractors sourcing against NSN 5305-00-928-9649. 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 B18.3 / B18.6.3, MIL-DTL / NASM / MS and AN series, ISO metric threads; common materials include carbon and alloy steel, 300/400-series stainless, and A2/A4 stainless per ISO 3506.

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