Aluminium alloys harden and become stronger during the bending process. As a result, thickness and bend radius are factors you need to consider.
- 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 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.
Read More: How To Bending Aluminum Without Cracking It
Minimum bending radius table
The Fabricator’s website 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 sheets.
The following is their specific content:
Aluminum alloy minimum bending radius table
In the chart diagram above with numbers that reflect the minimum inside bend radius for different alloys and tempers of aluminum. This chart shows a minimum bend radius of 0 to 1 times the material thickness for 0.125-in.-thick 5052-H32. This is slightly different from the recommendation you have from your aluminum supplier, but that’s no surprise. Variation is expected among different material producers. Regardless, 0 to 1 is a wide range of values, and the variation is amplified by temperature and the natural grain direction within the sheet.
The aluminum profile can be extruded and bent (cold bending aluminum) to specified tolerances or to standard dimensional tolerances. While a product’s dimensions and bend angles can be methodically measured and re-measured, the end product will only be as precise as the aluminum profile bending machine or method used.
Aluminum Minimum Bend Radii for 90 Degree Cold Forming of Sheet and Plateper The Aluminum Association, Inc. |
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| Alloy | Temper | RADII FOR VARIOUS THICKNESSES EXPRESSED IN TERMS OF THICKNESS “t” | |||||||
| 1/64 in. | 1/32 in. | 1/16 in. | 1/8 in. | 3/16 in. | 1/4 in. | 3/8 in. | 1/2 in. | ||
| 3003 | H12 | 0 | 0 | 0 | 1/2t | 1t | 1t | 1.5t | 2t |
| H14 | 0 | 0 | 0 | 1t | 1t | 1.5t | 2t | 2.5t | |
| H16 | 1/2t | 1t | 1t | 1.5t | 2.5t | 3t | 3.5t | 4t | |
| 3105 | H12 | 0 | 0 | 0 | 1/2t | 1t | 1t | 1.5t | 2t |
| H14 | 0 | 0 | 0 | 1t | 1.5t | 1.5t | 2t | 2.5t | |
| H16 | 1/2t | 1t | 1t | 1.5t | 2.5t | 3t | 3.5t | 4t | |
| 5052 | H32 | 0 | 0 | 1t | 1.5t | 1.5t | 1.5t | 1.5t | 2t |
| H34 | 0 | 1t | 1.5t | 2t | 2t | 2.5t | 2.5t | 3t | |
| H36 | 1t | 1t | 1.5t | 2.5t | 3t | 3.5t | 4t | 4.5t | |
| H38 | 1t | 1.5t | 2.5t | 3t | 4t | 5t | 5.5t | 6.5t | |
| 5086 | H32 | 0 | 1/2t | 1t | 1.5t | 1.5t | 2t | 2.5t | 3t |
| 5454 | O | 0 | 1/2t | 1t | 1t | 1t | 1.5t | 1.5t | 2t |
| H32 | 1/2t | 1/2t | 1t | 2t | 2t | 2.5t | 3t | 4t | |
| H34 | 1/2t | 1t | 1.5t | 2t | 2.5t | 3t | 3.5t | 4t | |
| 6061 | T6 | 1t | 1t | 1.5t | 2.5t | 3t | 3.5t | 4.5t | 5t |
Source: Aluminum Minimum Bend Radii
Read More: Minimum Recommended Bend Radius Chart of Aluminum and Steel Profiles
A Simple Rule of Thumb for Aluminum Minimum Bend Radius
There’s a rule of thumb to determine a steel’s minimum bend radius, and this generally works for aluminum too: Divide 50 by the material’s tensile reduction percentage as specified by your supplier. This value will vary by grade.
If the steel has a tensile reduction value of 10 percent, divide 50 by that value: 50/10 = 5. Next, subtract 1 from that answer: 5 – 1 = 4. Now, multiply that answer by the plate thickness. If the material is 0.5 in. thick: 4 × 0.5 = 2. So in this case, the minimum inside bend radius is 2 times the material thickness.
Works Cited: How to predict an air formed inside bend radius with precision, Bending Basics: The fundamentals of heavy bending