National Stock Number
Machine Screw — Screws (FSC 5305) · Part No. S503 AND S502
| National Stock Number | 5305-01-167-3291 |
|---|---|
| Item name | Machine Screw |
| Part number (commercial reference) | S503 AND S502 |
| Alternate references | PSN 91-556-1-02; 803-135828 PC4,; S503 |
| Unit of issue | EA |
| NIIN | 011673291 |
| NIIN assigned by | United States (NCB code 01) |
| Federal Supply Class (FSC) | 5305 — Screws |
| Federal Supply Group (FSG) | 53 — Hardware and Abrasives |
| Unit price (USD) | $7.00 |
| 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 machine screw. Confirm controlling dimensions against your drawing or standard sheet before ordering.
| Fastener Length | 0.282 Inches Minimum And 0.312 Inches Maximum |
|---|---|
| Head Style | Button |
| Nominal Thread Diameter | 0.500 Inches |
| Screw Material | Copper Alloy 464 Or Steel Comp 302 Or Steel Comp 302B Or Steel Comp 303 Or Steel Comp 303 Plus X Or Steel Comp 303Se Or Steel Comp 303Cu Or Steel Comp 303Ma Or Steel Comp 304 Or Steel Comp 304L |
| Thread Class | 2A |
| Thread Series Designator | Unf |
| Thread Quantity Per Inch | 20 |
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.
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 $7.00, this item sits below the class median of $10.52.
Stock activity. This item has appeared once in our supplier stock feed, most recently listed 2026-08-21, with a lot quantity of 1,603 units. Listing activity is a practical signal of ongoing availability; confirm current stock and firm pricing on your quote.
Typical applications. Structural and panel assembly, equipment enclosures, brackets, access covers, and virtually every mechanical assembly across ground vehicles, aircraft, ships, and support equipment.
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.
NSN 5305-01-167-3291 is supplied by Quick Brown Fox Solutions as a stock resale item. For custom-manufactured or prototype parts to your print, see our U.S.-based CNC machining services.
Country of origin: Türkiye (Turkey). Turkey is a NATO ally and a normal-trade-relations partner of the United States, and Turkish-origin end items are eligible for a wide range of U.S. federal and DLA procurements.
TAA note: Turkey is not a Trade Agreements Act (TAA) designated country, so these items are generally not eligible for TAA-covered solicitations. They are offerable under the Buy American Act and many non-TAA DLA buys. 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.
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