1. What is 6061 Aluminum Sheet?
Back in 1935 someone cooked up “Alloy 61S” and it quietly became the workhorse of aluminum world. Today pretty much every shop has 6061 aluminum sheet lying around. It’s a 6xxx series alloy – basically aluminum mixed with a bit of magnesium and silicon that turn into Mg₂Si particles when heat-treated. That’s what gives it the magic mix: decent strength, won’t rust away tomorrow, and you can actually machine or weld it without cursing all day.
People love it because the strength-to-weight numbers are solid, it’s cheap enough, and it doesn’t fight you in the shop.
2. Physical Properties of 6061 Aluminum Sheet
Density sits at 2.70 g/cm³ – about one-third of steel. Drop a 4×8 sheet on your foot and you’ll still walk, try that with mild steel and you’re calling an ambulance.
Typical chemistry looks like this (real mill sheet numbers, not textbook averages):
- Si 0.4-0.8%
- Mg 0.8-1.2%
- Cu 0.15-0.40%
- Fe max 0.7%
- The rest is aluminum and a pinch of other stuff
Leave it outside and a thin oxide skin forms in minutes. That skin is why your bike frame from 2005 still looks okay.
3. Mechanical Properties and Strength
If you’re buying aluminum sheet, nine times out of ten it’s T6. That means it got soaked at 530 °C, water-quenched, then baked again at 175 °C for 8 hours. Result? Around 310 MPa ultimate, 276 MPa yield, and 12-17% elongation before it snaps.
Quick real-world numbers most shops care about:
- 3mm T6 sheet: 45 ksi tensile
- 6mm T6 sheet: same strength, just thicker
- O-temper (soft): bends like butter, strength drops to ~124 MPa
T4 is in-between – bends easier than T6 but still has some guts.
4. Corrosion Resistance
Throw it in rain, splash seawater on it, leave it on a roof for ten years – still fine. Aluminum sheet runs especially clean because they control the iron and copper tight. That matters when you’re building a boat in Qingdao and don’t want pitting surprises after two seasons.
Alkaline soil or concrete with high pH? Yeah, it will pit. Anodize it or paint it and the problem disappears.
5. Operating Temperature
Normal life: no problem up to 150 °C. Above 200 °C it starts getting soft fast – don’t use it for exhaust manifolds. Weld it, heat-treat it, whatever – just don’t let it sit at 400 °C for hours unless you want spaghetti.
6. Why Shops Actually Pick 6061 Sheet
- Dirt cheap compared to 7075
- Every supplier has it in stock – call at 4 pm, pick up next morning
- Drills, mills, taps like mild steel but half the weight
- Weld it with 4043 or 5356 filler and it won’t crack on you
- Recycle guy pays almost the same as new price
One fabricator told me last month: “If the print doesn’t specifically call out 5052 or 7075, we just quote 6061 and sleep at night.”
7. Where You Actually See It
- Airplane wing skins and floor panels
- Yacht hulls and deck plates (especially 6-20 mm thick)
- Truck trailer decks and side walls
- Motorcycle frames, swingarms, triple clamps
- Base plates and gussets in every welding shop on earth
- Heat sinks when someone needs flat and cheap
8. Price Reality Check – December 2025
Right now 6061-T6 sheet runs roughly $3.50-$4.80/kg landed in most ports. 3 mm mill finish is the sweet spot. Go thicker than 25 mm and the price jumps. Want it cut-to-size, anodized, or with paper between sheets? Add 15-30%.
MINGTAI ALUMINUM’s typical FOB Qingdao quotes this week:
- 3 mm × 1500 × 3000 mm T6: ~$3.65/kg (10-ton lot)
- 10 mm same size: ~$3.85/kg
- 100 mm thick plate: call them, it’s a different conversation
Buy direct from the mill and skip two middlemen – saves real money once you’re over 5 tons.
We roll up to 2650 mm wide and 500 mm thick if you ever need something stupid big. Most people never do.
FAQ
Q: 6061-T6 vs 6061-T651 – what’s the real difference?
A: T651 just got stretched a couple percent after quenching to knock the internal stress out. Machine a big part from T6 and it might spring half a millimeter. T651 stays flat. Pay the extra 5-8% if flatness matters.
Q: Can you bend T6 aluminum sheet tight without cracking?
A: Rule of thumb: bend radius = 2-3× thickness. Need tighter? Order T4, bend it, then send it out for re-age to T6. Works every time.
Q: Where to actually buy good 6061 aluminum sheet in 2025 without headaches?
A:MINGTAI ALUMINUM ships mill-certified T6/T651 worldwide, up to 2650 mm wide, with proper 3.1 certificates. Price is usually sharper than the traders and the quality is consistent. Plenty of shops in the States and Europe keep buying container after container from them for a reason.
