Yield Strength of 6061-T6 Aluminium
| Value | 276,000,000 Pa |
| Status | Measured: ± 14,000,000 Pa (0.051 relative) |
| Source | Aluminum Design Manual / ASM Handbook, Vol. 2 |
| Categories | Material PropertiesEngineering & Trade |
| microbar | 2,760,000,000 μbar |
| barye | 2,760,000,000 Ba |
| millitorr | 2,070,170,200 mTorr |
| pascal | 276,000,000 Pa |
| millimeter of water column | 28,144,167 mmH₂O |
| pound per square foot | 5,764,379.8 lb/ft² |
| centimeter of water column | 2,814,416.7 cmH₂O |
| hectopascal | 2,760,000 hPa |
| millibar | 2,760,000 mbar |
| torr | 2,070,170.2 Torr |
| millimeter of mercury | 2,070,169.9 mmHg |
| inch of water column | 1,108,038.1 in w.g. |
| kilopascal | 276,000 kPa |
| foot of water column | 92,336.508 ft H₂O |
| inch of mercury | 81,502.754 inHg |
| pound per square inch | 40,030.416 psi |
| meter of water column | 28,144.167 m H₂O |
| decibar | 27,600 dbar |
| kilogram-force per square centimeter | 2,814.4167 kgf/cm² |
| bar | 2,760 bar |
| atmosphere | 2,723.9082 atm |
| megapascal | 276 MPa |
| kip per square inch | 40.030416 ksi |
| gigapascal | 0.276 GPa |
| million pounds per square inch | 0.040030416 Mpsi |
Learning zone
Aluminium has no sharp yield point, so its "yield" is defined by convention: the stress at 0.2 % permanent offset strain. For 6061 in the T6 temper — solution heat treated and artificially aged — that is 40 ksi (276 MPa), with 45 ksi ultimate and about 10 % elongation. Temper is everything: the same alloy in the O (annealed) condition yields at only 8 ksi, so a 6061 part is only as strong as its heat treatment history.
The trap is welding. Fusion welding 6061-T6 destroys the aging in the heat-affected zone, and the material there reverts toward annealed properties — codes require the welded zone to be designed at roughly 15–20 ksi yield unless the assembly is re-heat-treated after welding. Bolted and adhesive joints avoid the penalty entirely, which is why aluminium truck bodies and ladders are riveted or bolted rather than welded. Aluminium also lacks a fatigue endurance limit, so cyclic applications need a finite-life design rather than a stress below some threshold.