1050 and 1100 Aluminum Coil: When Pure Aluminum Fits.

What separates 1050 from 1100?

Both are 1xxx alloys, but they are separate registered compositions. The Aluminum Association registers 1050 with a minimum of 99.50 percent aluminum and 1100 with a minimum of 99.00 percent. The registration record on the Aluminum Association's Teal Sheets is the place to confirm the full composition limits of either one.

For a coil buyer the difference between the two is small next to the difference between 1xxx and the rest of the range. Which of them a specification names is a question for its author. If a drawing says only "1xxx" or "pure aluminum", ask which alloy it means before ordering. Check which designation your specification names.

What do 1050 and 1100 offer in a coil program?

High corrosion resistance and high formability, together with good electrical and thermal conductivity. Orbit's alloy overview also lists strong reflectivity for the series. These are the properties the 1xxx series is known for, and they are what a buyer is choosing when 1050 or 1100 is specified.

For where the 1xxx family sits against 3xxx and 5xxx in general, see the guide to the 1xxx, 3xxx and 5xxx series. This post stays with the two 1xxx alloys Orbit rolls.

What do you give up in strength?

Two different things are easy to run together. The first is yield and tensile strength, which govern denting and permanent deformation. They are lower for 1050 and 1100 than for the 3xxx and 5xxx alloys in Orbit's range, and heat treatment cannot raise them, so a 1050 or 1100 panel dents more readily in handling and under impact than a harder alloy of the same gauge would.

The second is elastic stiffness and flatness. Alloys have nearly the same elastic modulus, so gauge, panel size, support spacing and stiffening features govern deflection. Moving to a different alloy does not by itself make a large flat panel stiffer.

The lower strength is not a defect. It is the other side of the same trade that makes the alloy so easy to form. The mistake is to specify it for a part whose job is to resist denting or permanent deformation.

How does cold work set the strength of 1050 and 1100 coil?

Because the alloys are non-heat-treatable, strength is built by cold work during rolling and recorded in the H tempers. More cold work gives more strength and less formability, the same trade the alloy and temper guide describes for every alloy.

Describing the forming operation, including the bend radius the profile needs, is more useful than naming an H number by habit.

Where does pure aluminum fit in a coil program?

Orbit's alloy overview names signage, reflective parts and decorative parts as the uses where forming ease, surface quality or corrosion resistance matter more than load-bearing strength. Reflective parts draw on the strong reflectivity the series is listed for, and decorative parts draw on a metal that forms without cracking.

Flatness and coating choice matter for signage as well as alloy. The post on blank aluminum coil for signage covers those points.

When should the specification move to 3xxx or 5xxx?

When the part has to resist denting or permanent deformation, or needs more yield or tensile strength than the 1xxx series gives. The 3xxx alloys Orbit rolls, 3003 and 3105, offer more strength than 1xxx while keeping good formability and corrosion resistance. The 5xxx alloys, 5005, 5052 and 5754, extend the range further, with 5052 and 5754 offering higher strength again.

Moving up the range costs some formability, so check the bend radius the profile needs against the temper before committing. The series guide linked above sets the families side by side.

What should an inquiry for 1050 or 1100 coil include?

Give the supplier what it needs to confirm alloy, temper and form in one reply:

• The alloy, 1050 or 1100, or the forming requirement if the alloy is open
• The temper (available on request), or the forming operation if the temper is open
• Gauge, within Orbit's 0.20 to 2.00 mm rolled range, and width, up to 1650 mm (coated coil is up to 1.60 mm thick and 1350 mm wide)
• Mill finish, or the coating system and finish you have in mind
• Quantity against a minimum order of 6.5 MT plus or minus 10 percent, and destination

Coating availability on a given alloy and gauge is confirmed per specification. We respond to RFQs within one business day.

Common questions

References

• The Aluminum Association: International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys (Teal Sheets): the registration record for alloy designations and composition limits.