Mechanical Properties of Common Aluminum Grades

When you compare aluminum grades, what you are really comparing is a handful of numbers. This page is the mechanical properties table for the common aluminum grades — the tensile strength, yield strength and elongation of the grades buyers actually order, each at its working temper.

One caution up front: these are typical values, not acceptance minima. The minimum a supplier must meet is set by the product standard (ASTM B209, EN 485), and the mill certificate reports the measured values for the specific heat. Use this table to choose a grade; use the certificate to accept a lot.

Mechanical properties of common grades

The table tells the story of the alloy families at a glance: the 1xxx pure grades sit at the bottom of the strength scale and the top of the elongation scale; the 5xxx magnesium grades fill the middle with good strength and corrosion resistance; the heat-treatable 6xxx grades reach 300+ MPa; and 7075 tops out at 550 MPa. Each grade reference page carries the full composition and property detail.

How to read the three columns

Tensile strength is the maximum stress the material withstands before it breaks. It is the headline number most people quote, and the least useful on its own.

Yield strength is where the material stops springing back and starts deforming permanently. It is the number that actually matters for design, because a part that yields has failed even if it has not snapped.

Elongation is how far the material stretches before breaking, expressed as a percentage. High elongation means the material bends and forms without cracking; low elongation means it is strong but brittle in the bending sense. This is why 1050-O (37%) deep-draws and 7075-T651 (8%) does not.

The temper changes everything

A grade is not one material — it is a family of tempers, and the temper moves the strength as much as the grade does. 5052-O is 190 MPa and soft enough to form; 5052-H32 is 230 MPa and stiffer. The same grade at a different temper is a different design input.

Two temper effects worth memorizing:

1. Cold working raises strength and cuts elongation. H tempers (H12 through H18) strain-harden the metal; the higher the number, the harder and less ductile it is.
2. Heat treatment is a step change, not a glide. T4, T6 and T651 are heat-treated states that jump the strength up for the 6xxx and 7xxx grades, which is why 6061 in T6 (310 MPa) is a different material from 6061 in O.

The full temper map — O, H1x, H2x, H3x, T4, T6, T651 — is covered on the temper designations guide.

What the numbers cannot tell you

The tensile table hides the properties that decide real failures, and they are worth knowing before you choose on strength alone:

• Corrosion resistance. 5083 resists seawater; 7075 in T651 pits and stress-cracks in salt. No tensile number captures this.
• Weldability. 5052 and 5083 weld well; 7075 is effectively non-weldable. The table does not say so.
• Fatigue and toughness. The aerospace 2xxx and 7xxx grades earn their place on fatigue life, which a static tensile figure does not show.

So the honest way to use this table is as a first filter — sort by strength, then check the grade page for the corrosion, welding and forming behaviour that the strength number cannot express.

Choosing by the numbers

The values in this table are the same figures shown on each grade page, kept in one place so you can compare across grades without opening twelve tabs. For the composition limits and density that complete the picture, see the alloy reference pages. If you have a load case and want a grade recommendation, send the numbers — strength, environment and forming — and the choice usually falls out.