6061 vs 6063 aluminum: which should you buy?
6061-T6 is the stronger, do-everything aluminum: brackets, frames, machined parts. 6063-T5 is the architectural one: smoother surface, cleaner anodizing, easier bends, about half the yield strength. If the part carries load, buy 6061. If it's trim or railing people see, 6063 looks better.
What's the actual difference?
Strength and surface. Both are 6000-series aluminum, magnesium and silicon alloys that machine well and resist corrosion without any coating. The split is in the numbers: in the tempers we stock, 6061-T6 carries roughly double the yield strength of 6063-T5. In exchange, 6063 extrudes with a smoother surface, takes anodizing more evenly, and bends without complaining as much. Typical handbook values look like this:
| 6061-T6 | 6063-T5 | |
|---|---|---|
| Yield strength (typical) | About 40 ksi | About 21 ksi |
| Best at | Load: brackets, frames, machined parts | Looks: trim, railings, enclosures |
| Anodized finish | Good, can show streaks | Cleaner and more even |
| Bending | Can crack on tight radii in T6 | More forgiving |
| On our rack | Most shapes | Extrusion profiles |
When is 6061 the right buy?
When the part carries load or meets a cutting tool. Trailer brackets, gussets, machine bases, jigs, motor mounts, anything you'll drill and tap, anything with a bolt through it. 6061-T6 is the default aluminum for a reason: strong enough for real structure at half the weight of steel, and it machines beautifully. If you're unsure which one you need, buy 6061. Overbuilding trim costs a little; underbuilding a bracket costs the bracket.
When is 6063 the right buy?
When the metal is the part people see or touch. Railings, screen frames, door and window trim, LED channel, enclosure edges. 6063-T5 extrudes with that smooth architectural surface, anodizes cleaner than 6061, and bends on tighter radii without cracking. It's the alloy your finished edge wants to be. It just shouldn't be your load path: at about half the yield of 6061-T6, a 6063 bracket is a bracket on borrowed time.
Can you weld them?
Both weld fine with standard aluminum filler and AC TIG or a spool gun. The catch applies to both alloys: heat erases the temper, so the metal next to your weld drops well below its rated strength. Design welded aluminum joints with that in mind, or bolt where the load is serious. Either way, order your pieces a touch long and trim after fit-up: cut-to-length ordering makes that cheap to do.
What do we stock?
Our aluminum rack is mostly 6061-T6, across flat bar, round bar, square bar, angle, channel, sheet, pipe, and square and rectangle tube. 6063-T5 covers the extrusion profiles: angle, channel, square tube, rectangle tube, and round tubing, the shapes architectural work actually uses. We also stock 5052 and 3003 for sheet work that gets bent or welded. We don't carry aerospace alloys like 2024 or 7075; if a drawing calls for one, send a sourcing request and we'll quote it, sourcing runs 2-21 days. Choosing between metals entirely? Our 304 vs 316 stainless guide answers the same question for the salty side of the shop.
About Metals 'R' Us
Metals 'R' Us is a Canadian metal supplier in Dartmouth, Nova Scotia. Since 1997 we've sold steel, stainless, aluminum, brass, copper, bronze and tool steel, cut to the exact length you need. Pick your alloy, shape and size, type in your length in inches, and the price shows up right away. We ship pieces up to 96″ anywhere in Canada, with the best parcel rates under 48″, or you can pick up free at the shop in Dartmouth. $40 minimum order. Longer lengths (up to 21 feet), oversize loads, or custom plasma and CNC work? Send us a quick quote request and we'll price it for you.
Know which alloy your project wants? Shop aluminum and type your length in.