Metal Grades, Explained
The grades that cover most small-shop orders, with what each one is good at and where it lets you down.
Grades
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6061 Aluminum
The go-to machining and structural aluminum. Strong, weldable, anodizes clean.
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5052 Aluminum
Bends tight, welds clean, shrugs off salt water. The standard fabrication sheet.
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3003 Aluminum
Soft, formable, weather-resistant sheet. The usual alloy behind bright diamond tread plate.
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7075 Aluminum
Near-steel strength at aluminum weight. Machines beautifully; not a welding alloy.
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304 Stainless Steel
The everyday stainless for food equipment, trim and general fab. Forms and welds well.
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316 Stainless Steel
Molybdenum-bearing stainless for salt water, coastal air and chemical service.
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A36 Steel
The standard structural steel for plate, angle and channel. Welds easily, cuts clean.
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4140 Alloy Steel
Chromoly bar for shafts, pins and tooling. Annealed for machining or pre-hard ready to use.
Picking between two grades
Most grade questions come down to a pair. 6061 or 5052: machine it or bend it. 304 or 316: indoors or near salt and chlorides. A36 or A572-50: general fabrication or a design that needs the higher yield. Each grade page has a side-by-side comparison with its closest alternative.
For the tempers behind the letters and numbers (T6, H32, T651), see the aluminum alloy and temper guide.