Choosing aluminum stock for a shop project often comes down to two very different pieces: a thick 6061 plate for machining and a thin 3003 sheet for corrosion-resistant work. Both are new, both measure 12" x 24", and both meet ASTM B209, but they are built for different jobs. The biggest shock is the price difference: the 6061 plate comes in at $83.59, while the 3003 sheet is $29.58 - a gap of $54.01.
Quick Verdict
Choose the 6061 plate if you need a rigid, machineable blank that will hold threads and tolerances. Choose the 3003 sheet if you need a lightweight, corrosion-resistant panel and want to keep the project budget down.
Comparison Table
| Feature | 6061 Plate | 3003 Sheet |
|---|---|---|
| Price | $83.59 | $29.58 |
| Thickness | 1/4" | 1/16" |
| Alloy | 6061 | 3003 |
| Temper | T651 | H14 |
| Finish | Machined | Mill |
| Best For | Machining, solid blanks | Corrosion-resistant panels, lightweight parts |
Where Each Product Wins
The 6061 plate wins when your project involves cutting, drilling, or milling a solid block. Its T651 temper provides a stable, stress-relieved blank, and the machined finish means it's ready to mark and cut without stripping off a mill finish. The width and length tolerances allow +0.000 to +0.125", so you get a true rectangle for layout work.
The 3003 sheet wins when the part will be exposed to moisture or chemicals. The 3003 alloy's reputation for corrosion resistance, combined with an H14 temper, makes it a dependable choice for panels and enclosures. It's also easier to cut and form at 1/16" thick, and the mill finish keeps the cost down.
Product Notes
6061 Aluminum Plate, 1/4" x 12" x 24" Long, Solid Stock, Machining, T651
This listing includes one 1/4" x 12" x 24" plate made from 6061 aluminum in T651 temper. The width and length tolerances allow +0.000 to +0.125", which helps keep your layout square. The description explicitly notes that there will be normal scratches and nicks, and this item is not intended to have a finished surface. So if you need a show-ready piece, you'll need to deburr or sand it yourself. At $83.59, it's the more substantial investment, but for a solid stock piece that can handle machining operations without flexing, it's the stronger choice.
1/16" Thick Aluminum Plate Sheet 12" x 24" 3003 Alloy Stock Mill Finish NEW
This sheet is 12" x 24" and made from 3003 alloy in H14 temper with a mill finish. The description lists a typical yield strength of 21,000 psi and a tensile strength of 22,000 psi, so it can handle moderate structural duty. It also meets AMS 4008 and ASTM B209. The trade-off is that this is a sheet, not a plate, so it won't give you the rigidity needed for heavy machining stock removal. The mill finish may also show fingerprints or oxidation if left unprotected outdoors. But at $29.58, it's an affordable way to get a corrosion-resistant piece for brackets, panels, or internal supports.
Final Choice by Use Case
For machining fixtures, jigs, or parts that need a solid, flat base, choose the 6061 plate. For corrosion-resistant panels, weather-exposed brackets, or lightweight internal supports, choose the 3003 sheet. If budget is the deciding factor, the 3003 sheet costs $54.01 less, which can make a real difference on a larger order.
