Before discussing aluminum alloys, we should cover some background about the factors that affect their bendability. As you can imagine, products like aluminum foil, gutters, traffic signs, and automotive body parts, which are all made from aluminum alloys, have different bendability.

Three factors control the bendability of the various alloys in these products:

  • The formability of the aluminum alloy
  • Thickness and bend radius
  • Percent elongation

Let’s have a deeper look at these factors!

1st Factor – Formability

Formability is the ability of a given material to experience permanent deformation without the forming process cracking or tearing it. Permanent deformation is also known as plastic deformation in the materials science world.

Generally speaking, formability is a relative term and not a specific value. For example, the applied force necessary to shape a product depends on more than just the strength and ductility of a material. It also depends on factors such as the shape of the part and the thickness of the starting material.

In other words, we can measure the forming force to produce a specific part from a particular starting material. However, changing the shape of the part or the physical properties of the starting material will change the amount of force that needs to be applied.

2nd Factor – Thickness and Bend Radius

If you’ve handled regular aluminum foil, you’ll know that it is effortless to bend. However, if you had to bend a sheet of aluminum that was one-thousand times thicker than aluminum foil, it would be much harder! That is because the thicker a material is, the more difficult it is to bend.

You can also bend an aluminum gutter with your bare hands. But if you try to bend it to a tight angle without breaking it, you will have a hard time! Bending metal to a small bend radius has the potential to cause tearing or cracking.

The Fabricator offers certain key tables and general rules which are helpful for understanding the limits to bendability for specific aluminum alloys. You can use these to determine the minimum allowable bend radius for particular thicknesses of aluminum sheet.

3rd Factor – Percent Elongation

Percent elongation represents the ability of the material to be plastically deformed under tension. It is also known as plastic strain or stain applied beyond the yield strength limit of a material.
The more ductile aluminum alloys can experience more significant plastic deformation with small increases in applied stress. This results in better overall aluminum bendability.

Like the other properties, the percent elongation varies for each alloy. Take a look at the stress-strain curve above. You’ll see that annealed aluminum alloy 3003 (shown as AA3003-O) has a very high percent elongation (strain %) of roughly 35%. It has very high bendability relative to other alloys.


3 of the Best Aluminum Alloys for Bending

Numerous metal alloying agents can be combined with aluminum to produce different aluminum alloys. The system for naming them uses four digits, with the first digit representing their chemical composition. We explain this in our article on aluminum alloy designations and tempers.

Generally speaking, aluminum alloys from the 1XXX, 3XXX, and 5XXX series demonstrate better bendability than other aluminum alloys. Some 6XXX series alloys are fairly bendable as well.

However, the different properties offered by each may make some more desirable than others. For example, 1XXX series aluminum generally has poor mechanical properties and is not suited to structural applications.

Now let’s discuss which alloys offer the best bendability and when you should use them.

#1 – Aluminum Alloy 3003

This alloy is primarily alloyed with manganese and is one of the most commonly used aluminum alloys for bending applications. It has excellent formability properties and does not require heat to be bent or molded.

Companies often make gutters, roofing, siding, chemical equipment, and storage tanks from 3003 aluminum.

#2 – Aluminum Alloy 5052

With magnesium as the primary alloying element, AA5052 demonstrates moderate-to-high strength characteristics. At the same time, it retains good bendability, and designers can use it for more intensive applications than AA3003. The corrosion resistance of this alloy is also excellent against seawater, meaning it is excellent for applications in marine equipment.

Manufacturers often produce hydraulic tubes, traffic and hardware signs, medical equipment, marine equipment, and electronics (chassis and enclosures).

#3 – Aluminum Alloy 6061

You will find this is an extremely common alloy in your day-to-day life. Even though it is not as bendable or formable as the two alloys above, it is the strongest among all three. It has magnesium and silicon as alloying elements, and you can further enhance its strength with heat treatment.

Alloy 6061 is widely referred to as “structural aluminum” because it is so commonly used in structural (construction) applications. Nevertheless, due to its outstanding properties, it is also used in food and beverage containers, ladders, aircraft and automotive parts, scuba tanks, bicycle frames, and more.

Why Are These 3 Alloys Important?

Despite their different properties, these alloys are excellent examples of bendability in aluminum alloys. They demonstrate that even though some aluminum alloys feature better formability and percent elongation for a given bend radius and thickness, they each serve a unique purpose and a wide variety of applications.

Even with slightly lower bendability, the strength of alloy 6061 makes it one of the most widely used aluminum alloys. In the same way, alloy 3003 has multiple uses in applications that require superior bendability. Meanwhile, alloy 5052 is commonly used thanks to its balance in terms of bendability and strength.

Explanation of aluminum plate grade

1000 series representative

1050, 1060, 1070, 1000 series aluminum plate is also called pure aluminum plate.Among all series, 1000 series belongs to the series with the most aluminum content.The purity can reach more than 99.00%.

Because it does not contain other technical elements, the production process is relatively single and the price is relatively cheap.It is the most commonly used series in conventional industry at present.At present, most of the products in circulation in the market are 1050 and 1060 series.

The minimum aluminum content of the 1000 series aluminum plate is determined according to the last two Arabic numerals. For example, the last two Arabic numerals of the 1050 series are 50.According to the international brand naming principle, the aluminum content must reach 99.5%, and the above is regarded as qualified products.China’s aluminum alloy technical standard (GB / t3880-2006) also clearly stipulates that the aluminum content of 1050 must reach 99.5%.Similarly, the aluminum content of 1060 series aluminum plates must reach more than 99.6%.

1000 series typical brand and application:Pure aluminum plate 1060 is mainly used in occasions requiring high corrosion resistance and formability, but for parts with low strength, such as chemical equipment, marine equipment, railway oil tank car, conductor materials, instrument materials, welding rods, etc.

2000 series aluminum plate representative

2A16 (LY16), 2A06 (LY6) and 2000 series aluminum plates are characterized by high hardness, of which the original content of copper is the highest, about 3-5%.

2A12 aluminum alloy is a kind of high strength hard aluminum, which can be strengthened by heat treatment; 2A12 aluminum alloy has good spot weldability and tends to form intergranular cracks when gas welding and argon arc welding are used;

2A12 aluminum alloy has good machinability after cold work hardening.

The corrosion resistance is not high. Anodizing and painting methods or aluminum coating on the surface are often used to improve corrosion resistance.

2000 series aluminum plate belongs to aviation aluminum material, which is not often used in conventional industry at present.

At present, there are few manufacturers producing 2000 series aluminum plates in China.The quality cannot be compared with that of foreign countries.

At present, imported aluminum plates are mainly provided by Korean and German manufacturers.With the development of China’s aerospace industry, the production technology of 2000 series aluminum plate will be further improved.

3000 series aluminum plate representative

3000 series aluminum plates are mainly represented by 30033003 and 3A21. It can also be called antirust aluminum plate.The production process of 3000 series aluminum plate in China is excellent. 3000 series aluminum plate is mainly composed of manganese.The content is between 1.0-1.5. It is a series with good antirust function.It is commonly used in humid environments such as air conditioner, refrigerator and underbody. The price is higher than 1000 series. It is a more commonly used alloy series.

3000 series typical grade and its application:

3003 aluminum is mainly used for processing parts requiring good molding performance, high corrosion resistance, or good weldability, or workpieces requiring higher strength than 1000 series alloy, such as tanks and tanks for transporting liquid, pressure tanks, storage devices, heat exchangers, chemical equipment, aircraft fuel tanks, oil duct, reflective plates, kitchen equipment, washing machine cylinder block, rivet, welding wire.

3004 aluminum requires higher parts than 3003 alloy, chemical product production and storage devices, sheet processing parts, building baffles, cable ducts, sewers and various lamp parts.

4000 series aluminum plate representative

The 4000 series aluminum plate represents the 4a014000 series aluminum plate, which belongs to the series with high silicon content.

Generally, the silicon content is between 45-6.0%.It belongs to building materials, mechanical parts, forging materials and welding materials; Low melting point and good corrosion resistance.Product features: heat resistance and wear resistance.

5000 series representative

The 5000 series represents 5052, 5005, 5083 and 5A05 series.

5000 series aluminum plate belongs to the commonly used alloy aluminum plate series.The main element is magnesium, and the magnesium content is between 3-5%. It can also be called aluminum magnesium alloy.The main features are low density, high tensile strength and high elongation.

Under the same area, the weight of aluminum-magnesium alloy is lower than that of other series, so it is often used in aviation, such as aircraft fuel tank.

It is also widely used in conventional industry. The processing technology is continuous casting and rolling, which belongs to the hot-rolled aluminum plate series, so it can do deep oxidation processing.

In China, the 5000 series aluminum plate is one of the more mature aluminum plate series.

5000 Series typical grade and its application:

5052 aluminum has good forming and processing performance, corrosion resistance, weldability, fatigue strength and medium static strength. It is used to manufacture aircraft fuel tank, oil pipe, sheet metal parts, instruments, street lamp supports, rivets, wires, etc.

6000 series representative

6061 mainly contains magnesium and silicon, so it integrates the advantages of 4000 series and 5000 series.

6061 is a cold-treated aluminum forging product, which is suitable for applications requiring high corrosion resistance and oxidation resistance.

Good usability, excellent interface characteristics, easy coating and good processability.

It can be used for low-pressure weapons and aircraft joints.

General features of 6061: excellent interface features, easy coating, high strength, good usability and corrosion resistance.

Typical uses of 6061 aluminum: aircraft parts, camera parts, couplers, ship accessories and hardware, electronic accessories and connectors, decorative or various hardware, hinge head, magnetic head, brake piston, hydraulic piston, electrical accessories, valves and valve parts.

7000 series representative

7075 mainly contains zinc. It also belongs to Aviation series. It is aluminum magnesium zinc copper alloy, heat treatable alloy, superhard aluminum alloy and has good wear resistance.

7075 aluminum plate is stress relieved and will not deform and warp after processing.

All super large and super thick 7075 aluminum plates are detected by ultrasonic, which can ensure that there are no sand holes and impurities.

7075 aluminum plate has high thermal conductivity, which can shorten the forming time and improve the work efficiency.

7075 is mainly characterized by hardness.

7075 is a high hardness and high strength aluminum alloy, which is commonly used in the manufacture of aircraft structure and futures.

It requires the manufacture of high stress structural parts and molds with high strength and strong magic corrosion resistance.

At present, it basically depends on imports, and China’s production technology needs to be improved.

8000 Series

The more commonly used 8011 belongs to other series.

In my memory, it is an aluminum plate whose main function is to make a bottle cap. It is also used in radiators. Most applications are aluminum foil, which is not commonly used.

Air Bending Force Chart Background

The air bending force chart records the standard lower die V width and required bending force corresponding to the bending of different sheet metals, and has already become ageneral specification in the industry.

However, there was no such specification at the earliest time.Each press brakemanufacturer decided to use the V-width based on their own experience.

At that time, Amada collected and summarized the experience data of customers from allwalks of life around the world, and finally made the following most authoritative bendingforce chart for bending process.

Air Bending Force Chart-Mild Steel

Air Bending Force Chart-Stainless Steel

You can also use our press brake tonnage calculator to calculate the required bendingforce for your sheet metal products.


How to Calculate Press Brake Machines Tonnage? For determining the hydraulic bending force or the tonnage of the press brake that is required to bend the sheet metal in a specific thickness you have totally the following TWO methods:

By the press brake tonnage chart

By the bending force calculation formula

Only after the tonnage of the press brake confirmed, then you can spend your time taking other factors (press brakecomponents, toolings, controllers, etc) into consideration before making your decision to purchase the press brake.In this article, we will show you how to determine the required bending force by your sheet metal.


1.Press Brake Tonnage Chart


The following press brake tonnage chart is used by many press brake manufacturers both in China and abroad countries.
We know that many press brake suppliers are using a different chart, but most of them are similar and the final resultwill almost the same. So just take one of them as your reference.

Note: if there are no special requirements for the bending radius, the slot width v should be 8-10 times plate thickness.The tonnage as shown in the above press brake tonnage chart is calculated based on the sheet metal with the tensilestrength ob=450N/mm2 and length L=1m.
Now you have the bending force chart, the question is how to find the press brake tonnage in the above chart?
First,you need to know what does “s””V”“B”“R”means in the above chart. Check out the following pictures you will understand what do they mean.

  • P= Bending force
  • S = Thickness of sheet
  • V = Vee opening of the bottom die
  • B = Min bending flange
  • R = Inner radius


If the thickness of your metal sheet S =4mm, generally the vee opening of the bottom die is 8 times the thickness of the sheet.However, for the thicker plate, the vee opening should be bigger.The following recommend vee opening of the bottom die can be your reference.

S 0.5-3mm 3-8mm 9-10mm >12mm
V 6S 8S 10S 12S

Now we back to the chart, find the S data in the chart which is “4” ,and now we know the “”V” should be 4*8=32.And you can see that the intersection of the row and column where the “s” and v”stay is “330” . The unit of”330”is“KN”.

Now we know that for bending the sheet metal with 4mm thickness and 1m length, the required tonnage is 330KN.lf bend the 4mm sheet in 3 meters, then the tonnage should be 330*3=990KN, which equals to 101 Ton.

Here we come to the conclusion: you should choose at least 100ton press brake. However, we recommend you tochoose the bigger tonnage like 120Ton because if the press brake works in full load for a long time, the service life of the machine will be shortened.


2.Bending Force Calculation Formula

For example:
Plate thickness S=4mm, width L=3m, ob=450N/mm2 Generally slot width V=S*8
Therefore P=650*4*4*3/4*8=975(KN)= 99.5(Ton)
The result is very close to the data in the bending force chart.
As you can see, method #1 to calculate the press brake tonnage is based on the mild steel material.What if the material is stainless steel, aluminum or brass?
lt’ s simple, multiply the results calculated by the above formula by the coefficients in the following table:

Material Mild steel Stainless steel Aluminum Brass
Coefficients 1 1.6 0.65 0.5



Another press brake tonnage calculation formula is: P=1.42obS*L/v

P: bending force (KN)

S: plate thickness (mm)

L: plate width(m)

V: bottom die slot width (mm)

ob: tensile strength (Mpa)

For example:
Plate thickness S=4mm, width L=3m, ob=450N/mm2,Generally slot width V=S*8

Therefore P=1.42*450*4*4*3/4*8=958.5(KN)= 96 (Ton) For bending the sheet metal with different materials, the key point is to find out the tensile strength of the specific material, then you will get the required bending force by the above formula.

The tensile strength table below can be the reference:

     Material               Soft(N/mm2) Hard(N/mm2)
Lead 25-40

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Tin 40-50
Aluminum 93 1710
Aluminum Alloy Type 4 230 480
Duralumin 260 480
Zinc 150 250
Copper 220-280 300-400
Brass(70:30) 330 530
Brass(60:40)) 380 490
Phosphor Bronze/Bronze 400-500 500-750
Nickel Silver 350-450 550-700
Cold Rolled Iron 320-380
Steel .1% Carbon 320 400
Steel .2% Carbon 400 500
Steel .3% Carbon 450 600
Steel .4% Carbon 560 720
Steel .6% Carbon 720 900
Steel .8% Carbon 900 1100
Steel 1.0% Carbon 1000 1300
Silicon Steel 550 650
Stainless Steel 650-700
Nickel 440-500 570-630