As listed
| Field | Value |
|---|---|
| Seller | Aircraft Spruce |
| Material | 4130 chromium-molybdenum steel |
| Specification | MIL-S-6345A normalized (formerly MIL-S-18729C) |
| Thicknesses | 0.025" to 0.250" |
| Substitution | Annealed may be substituted if normalized is unavailable (per the listing) |
| Tensile strength (listed) | 75,000–85,000 psi, as stated by Spruce |
| Listing checked | 2026-09-30 |
Taken from Aircraft Spruce's product page on 2026-09-30. Where the listing does not state a figure, this table does not either.
What it is for
Same substitution clause as LAS's 4130 sheet: if the condition matters, say so on the order.
The tensile range is the seller's figure, not one traced to a primary source.
Sizes listed
| Thickness | Size (in.) | Part No. |
|---|---|---|
| .025 | 6 x 12 | 03-21800 |
| .025 | 9 x 9 | 03-21850 |
| .025 | 9 x 18 | 03-21900 |
| .025 | 18 x 18 | 03-22000 |
| .025 | 18 x 36 | 03-22100 |
| .025 | 18 x 72 | 03-22150 |
| .032 | 6 x 12 | 03-22510 |
| .032 | 9 x 9 | 03-22515 |
| .032 | 9 x 18 | 03-22520 |
| .032 | 18 x 18 | 03-22525 |
| .032 | 18 x 36 | 03-22530 |
| .032 | 18 x 72 | 03-22535 |
| .040 | 6 x 12 | 03-22600 |
| .040 | 9 x 9 | 03-22650 |
| .040 | 9 x 18 | 03-22700 |
| .040 | 18 x 18 | 03-22800 |
| .040 | 18 x 36 | 03-22900 |
| .040 | 18 x 72 | 03-22950 |
| .040 | 8 x 8 | 03-56302 |
| .040 | 12 x 12 | 03-56304 |
| .040 | 20 x 12 | 03-56316 |
| .040 | 26 x 10 | 03-56312 |
| .040 | 12 x 24 | 03-56306 |
| .040 | 14 x 30 | 03-56308 |
| .040 | 18 x 30 | 03-56310 |
| .050 | 6 x 12 | 03-23000 |
| .050 | 9 x 9 | 03-23050 |
| .050 | 9 x 18 | 03-23100 |
| .050 | 18 x 18 | 03-23200 |
| .050 | 18 x 36 | 03-23300 |
| .050 | 18 x 72 | 03-23350 |
| .050 | 4 x 24 | 03-56320 |
| .050 | 12 x 12 | 03-56318 |
| .050 | 8 x 24 | 03-56322 |
| .050 | 12 x 24 | 03-56324 |
| .063 | 6 x 12 | 03-23400 |
| .063 | 9 x 9 | 03-23450 |
| .063 | 9 x 18 | 03-23500 |
| .063 | 18 x 18 | 03-23600 |
| .063 | 18 x 36 | 03-23700 |
| .063 | 18 x 72 | 03-23750 |
| .063 | 10 x 10 | 03-56326 |
| .063 | 10 x 14 | 03-56332 |
| .063 | 12 x 12 | 03-56328 |
| .063 | 12 x 24 | 03-56330 |
| .071 | 6 x 12 | 03-23800 |
| .071 | 9 x 9 | 03-23850 |
| .071 | 9 x 18 | 03-23900 |
| .071 | 18 x 18 | 03-24000 |
| .071 | 18 x 36 | 03-24100 |
| .071 | 18 x 72 | 03-24150 |
| .071 | 4 x 4 | 03-56334 |
| .071 | 12 x 12 | 03-56336 |
| .071 | 12 x 24 | 03-56338 |
| .080 | 6 x 12 | 03-24200 |
| .080 | 9 x 9 | 03-24250 |
| .080 | 9 x 18 | 03-24300 |
| .080 | 18 x 18 | 03-24400 |
| .080 | 18 x 36 | 03-24500 |
| .080 | 18 x 72 | 03-24550 |
| .080 | 2 x 10 | 03-56354 |
| .080 | 12 x 24 | 03-56340 |
| .090 | 6 x 12 | 03-24600 |
| .090 | 9 x 9 | 03-55500 |
| .090 | 9 x 18 | 03-24700 |
| .090 | 18 x 18 | 03-24800 |
| .090 | 8 x 36 | 03-24900 |
| .090 | 18 x 72 | 03-24950 |
| .090 | 2 x 10 | 03-56344 |
| .090 | 6 x 8 | 03-56342 |
| .090 | 12 x 24 | 03-56346 |
| .100 | 6 x 12 | 03-25000 |
| .100 | 9 x 18 | 03-25100 |
| .100 | 18 x 18 | 03-25200 |
| .100 | 18 x 36 | 03-25300 |
| .100 | 18 x 72 | 03-25350 |
| .125 | 6 x 12 | 03-55300 |
| .125 | 9 x 9 | 03-25370 |
| .125 | 9 x 18 | 03-25400 |
| .125 | 18 x 18 | 03-25500 |
| .125 | 18 x 36 | 03-25600 |
| .125 | 18 x 72 | 03-25650 |
| .125 | 10 x 24 | 03-56348 |
| .125 | 12 x 24 | 03-56350 |
| .190 | 9 x 9 | 03-25660 |
| .190 | 9 x 18 | 03-25700 |
| .190 | 18 x 18 | 03-25750 |
| .190 | 18 x 36 | 03-26025 |
| .250 | 9 x 9 | 03-25850 |
| .250 | 9 x 18 | 03-25900 |
| .250 | 18 x 18 | 03-25950 |
| .250 | 18 x 36 | 03-26050 |
| .250 | 18 x 72 | 03-00106 |
As listed by Aircraft Spruce on 2026-09-30. Check the live listing before ordering: stock and part numbers change.
Where to buy
The link opens Aircraft Spruce's own page for this item, so the price and stock you see are theirs and current. We do not copy prices.
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Sources
- Aircraft Spruce — 4130 Steel Sheets — product listing, checked 2026-09-30.