Aluminum Alloy Properties: Key Data for Industrial T-Slot Profile Selection

Material Engineering Notes, Industrial Framing Series

A 6063-T5 bar extruded at around 480 degrees Celsius and cooled in still air reaches a yield strength near 145 MPa while weighing only 2.70 g/cm3, about one third the density of steel. Those two numbers explain most decisions in industrial framing projects covering machine bases, guarding, workstations, and conveyor structures. Aluminum alloy properties, however, are never a single number on a datasheet. They are a set of trade-offs among strength, weight, corrosion resistance, conductivity, and manufacturability, and the wrong balance shows up quickly as a frame that deflects under load or a surface that stains in a wet workshop. At Shanghai Huishuo Aluminum Industry Technology Co., Ltd., profile selection conversations start from these properties, because the alloy and temper chosen at the die stage decide everything that follows: wall thickness options, load class, finish quality, and final cost. This guide sets out the properties that matter, compares the common alloy families with real figures, and turns those figures into a practical ordering checklist.

Content

1 What Aluminum Alloy Properties Mean for Industrial Profile Buyers
2 Aluminum Alloy Properties Compared: 6063 vs 6061 vs 7075
3 Why Heat-Treatable 6-Series Alloys Dominate Industrial Extrusion
4 Matching Aluminum Alloy Properties to Wall Thickness and Load Class
5 Frequently Asked Questions About Aluminum Alloy Properties

What Aluminum Alloy Properties Mean for Industrial Profile Buyers

Aluminum alloy properties are the measurable characteristics of a given alloy, including density, strength, corrosion resistance, conductivity, and workability, that decide whether it will survive a specific application.

Pure aluminum is soft and ductile, ideal for foil and conductor cable but nearly useless for a load-bearing frame. Alloying changes that. Controlled additions of magnesium, silicon, copper, manganese, or zinc, combined with the right working and heat treatment, lift ultimate tensile strength from roughly 90 MPa in commercial-purity 1100 to about 570 MPa in 7075-T6, while density stays close to 2.70 g/cm3 across almost the whole range.

Definition. An aluminum alloy is aluminum combined with controlled additions of one or more elements, most commonly magnesium, silicon, copper, manganese, or zinc, to improve strength, formability, and corrosion resistance beyond what pure aluminum delivers.

Density and strength-to-weight ratio. Most wrought alloys sit between 2.68 and 2.81 g/cm3, which is why an aluminum frame weighs about one third of the equivalent steel structure.
Mechanical strength. Yield strength spans roughly 35 MPa for annealed 1100 up to 500 MPa for 7075-T6, with heat-treatable 6xxx grades covering the 145 to 270 MPa band most framing projects need.
Corrosion resistance. A natural oxide film only a few nanometers thick re-forms within minutes of a scratch, giving aluminum its signature durability in humid and outdoor service.
Thermal and electrical conductivity. Typical 6xxx alloys transfer about 200 W/mK of heat and carry around 55 percent IACS, enough for heatsinks, busbars, and enclosed electronics.
Workability. Metals handbooks such as those from ASM International rank aluminum among the easiest engineering metals to extrude, form, and machine, which is exactly why intricate T-slot cross-sections stay economical.
Response to surface treatment. Anodizing grows the natural film into an engineered layer of 5 to 25 micrometers, adding wear resistance, color options, and a stable surface for factory environments.

2.70 g/cm3

Typical density of 6xxx profiles

570 MPa

Peak tensile strength, 7075-T6

55%

IACS conductivity of 6063-T5

Aluminum Alloy Properties Compared: 6063 vs 6061 vs 7075

For industrial T-slot framing, the practical decision comes down to 6063 for standard profiles and 6061 where higher loads or heavy CNC machining are involved.

The four-digit designation announces the main alloying element: 1xxx is commercial purity, 2xxx copper, 3xxx manganese, 5xxx magnesium, 6xxx magnesium plus silicon, and 7xxx zinc. Each family trades extrudability against strength in a predictable way, and the table below collects typical room-temperature values.

Approximate typical room-temperature values for common wrought alloys; exact limits depend on standard, product form, and section thickness
Alloy and temper	Main alloying elements	Tensile strength	Yield strength	Density	Typical use
1100-O	99.0 percent Al minimum	90 to 130 MPa	35 MPa	2.71 g/cm3	Foil, chemical and food equipment
5052-H32	2.5 percent Mg	230 MPa	195 MPa	2.68 g/cm3	Sheet metal, marine and transport parts
6063-T5	Mg 0.45 to 0.9, Si 0.2 to 0.6	185 MPa	145 MPa	2.70 g/cm3	T-slot profiles, architectural framing
6061-T6	Mg 0.8 to 1.2, Si 0.4 to 0.8	310 MPa	270 MPa	2.70 g/cm3	Structural parts, CNC machined components
7075-T6	Zn 5.1 to 6.1, Mg 2.1 to 2.9, Cu 1.2 to 2.0	570 MPa	500 MPa	2.81 g/cm3	Aerospace and high-stress tooling

When a project sits between those two 6-series workhorses, the deciding factors are press-quench response and machining volume. We compare them in detail in our 6061 versus 6063 technical selection guide.

Typical Ultimate Tensile Strength by Alloy and Temper

1100-O

110 MPa

5052-H32

230 MPa

6063-T5

185 MPa

6061-T6

310 MPa

7075-T6

570 MPa

Typical mid-range figures compiled from public alloy datasheets

Takeaway

Strength follows alloying content, while extrudability follows purity. 7075-T6 delivers roughly three times the tensile strength of 6063-T5, but its zinc and copper content rules it out for the thin, intricate ribs of a T-slot die, and its 2.81 g/cm3 density quietly gives back part of the weight advantage.

Why Heat-Treatable 6-Series Alloys Dominate Industrial Extrusion

The 6xxx family dominates industrial extrusion because magnesium and silicon form Mg2Si precipitates that respond to heat treatment, so the alloy gains real strength while remaining soft enough to push through complex dies at 450 to 500 degrees Celsius.

The metal leaves the die soft, and what happens over the next few hours sets the final aluminum alloy properties. In the T5 temper the profile is cooled at the press with forced air and then aged, which keeps distortion low across long, slender framing members. In the T6 temper the profile is water quenched and artificially aged at roughly 180 degrees Celsius, which raises strength but also locks in more residual stress, a real consideration on thin walls.

6063-T5

Forced air cooling at the press exit
Natural or single-stage artificial aging
About 185 MPa tensile, 145 MPa yield
Low distortion, standard choice for T-slot profiles

6063-T6

Water quench, then aging near 180 degrees Celsius
About 240 MPa tensile, 215 MPa yield
Roughly 20 to 30 percent stronger than T5
Preferred for high-load frames and machined parts

This is why the standard range of industrial aluminum extrusion profiles from a specialist mill is built almost entirely on 6063, with 6061 reserved for heavy structural members and CNC-machined plates.

Temper is not a footnote on the purchase order. T5 and T6 start from the same billet and the same die, and the cooling path alone moves yield strength by up to 30 percent.

Matching Aluminum Alloy Properties to Wall Thickness and Load Class

Once the alloy and temper are fixed, wall thickness and series size become the practical levers for tuning load capacity, stiffness, and cost.

Two 4040 profiles with identical outer dimensions can differ by more than 60 percent in wall thickness, from a 2.0mm economical wall to a 3.2mm high-strength wall. Deflection is governed by the moment of inertia of the cross-section, so the thicker wall holds alignment noticeably longer under the same load.

HS-8-4040F Economical 4040 T-Slot Aluminum Profile with 2.0mm WallWith a 40x40mm cross-section, 2.0mm wall, and 8.2mm slot, this economical profile suits cost-sensitive builds. It contrasts with thicker-wall 4040 variants discussed nearby, offering a budget-friendly option for light frames.View Product →

HS-8-4040D High-Strength 4040 Profile with 3.2mm Thickened WallThis 3.2mm-wall 4040 profile weighs 1.88kg/m and resists deflection under heavy loads, directly illustrating the thicker-wall advantage described above. Its no-hole design allows flexible drilling for custom heavy-duty frames.View Product →

Slot width matters as well: a 10.2mm wide slot carries heavier t-nuts and bolts than a 6mm slot, which is why 45 and 50 series profiles anchor most large-span and extra-heavy-duty builds. At the other end of the scale, laboratories and light enclosures prioritize weight and clean handling over raw capacity, which is where thin-wall 3030 variants earn their place.

HS-8-3030QL Lightweight 3030 T-Slot Profile for Laboratory StructuresAt just 0.58kg/m with a 1.4mm wall, this 30x30mm profile fits the light laboratory and enclosure applications mentioned nearby, where weight savings and clean handling matter more than maximum load capacity.View Product →

60%

Wall thickness spread between economical and high-strength versions of the same 4040 outer profile, and the fastest way to add load reserve without changing series.

Define the load, span, and operating environment before opening a catalog.
Default to 6063-T5 for standard framing; step up to T6 or 6061-T6 when loads or machining demands rise.
Choose the series by slot width and load class rather than by outer size alone.
Pick the lightest wall thickness in that series that still meets your deflection target.
Specify anodized silver or black at the same time as the profile, since late finish decisions are a common cause of rework.

Frequently Asked Questions About Aluminum Alloy Properties

What are the main properties of aluminum alloys?

The headline properties are low density at about 2.70 g/cm3, tensile strength between roughly 90 and 570 MPa depending on series and temper, strong corrosion resistance from the self-repairing oxide film, high thermal and electrical conductivity, and excellent extrudability and machinability.

Which aluminum alloy is best for industrial T-slot profiles?

6063 in T5 or T6 temper is the industry default because it extrudes cleanly into thin, precise slots and anodizes evenly. 6061-T6 is the step-up choice for high-load frames and parts that need substantial CNC machining.

What is the difference between 6063-T5 and 6063-T6?

Both start as the same extrusion. T5 is air cooled at the press and aged, reaching about 185 MPa tensile strength, while T6 is water quenched and artificially aged, reaching about 240 MPa. The trade-off is slightly higher distortion risk with T6 on thin sections.

Does anodizing change the mechanical properties of aluminum?

No. Anodizing converts the surface into a 5 to 25 micrometer oxide layer that improves corrosion resistance and surface hardness, but it does not alter the bulk strength of the profile.

Bottom Line

Specifying by numbers works: 2.70 g/cm3 density, a 145 to 270 MPa yield band in the 6xxx family, and a 5 to 25 micrometer anodic film cover the majority of industrial framing decisions.