How do you bend parts?

Learn how we bend sheet metal and polycarbonate with a process known as air bending!

How we bend parts with air bending

While a flange is being formed, there are just three points of contact between the material and the tooling: the punch and two sides of the die.

An air gap is present in the die’s trough under the flange’s apex, which gives the process its name.

Air gap and points of contact during air bending process

Effect on bend radii

With air bending, the effective radius is determined by the tooling combination (die + punch) and a material’s thickness and strength. Depending on your material choice, the effective radius (the internal radius after bending) may be smaller for a thicker gauge, or vice versa. 

Find our effective bend radii on each material page in the material specifications and properties.

You can also reference radiuses and other specifications for all materials we bend in our handy Bending Calculator specification chart.

Polycarbonate limitations with air bending

To bend polycarbonate, flanges must be overbent to achieve the desired angle due to the spring back of the material. This means that some designs that can be formed in sheet metal may not be feasible in plastic.

Learn more about polycarbonate bending considerations.

In the example shown here, the material is bent 120-130 degrees to achieve a 90-degree angle.

What about gradual bends, curved parts, or custom bend radiuses?

Since we use air bending exclusively, we’re unable to form large gradual bends or compound curves. We do not offer custom bend radii at this time.

Start your bent project!

Now that you know more about our process, be sure to review all of our bending design guidelines before uploading your part file to our website for an instant quote. If you have questions about bend file setup reach out to our Support team anytime!

Start your first SendCutSend project today!

Upload your CAD design or use our parts builder and get instant pricing on your custom laser cut parts, all delivered to your door in a matter of days.

We proudly use hardware by PEM

Flush Standoff, 4-40, .250" Zinc plus Clear Chromate

Aluminum: 5052, 6061, 7075 Steel: Mild, G30

SKUSO-440-8
Thread Size4-40 x .250″
Hole size in sheet (+0.003/-.0.000).168″
Minimum sheet thickness0.040″
Maximum sheet thickness.125″
Fastener materialSteel
Minimum distance hole C/L to edge or bend.250″
When determining the distance between two or more fasteners, you can calculate the distance by the formula, C/L to edge + 1/2 the diameter of the second mounting hole..345″
Recommended panel materialSteel/Aluminum
Coating typeZinc
Length.250″
Aluminum material ranges (5052, 6061, 7075)0.040″-0.125″
Steel material ranges (CRS, HRPO, HR)0.048″-0.119″

We proudly use hardware by PEM

Flush Standoff, 4-40, .250" Passivated

Stainless Steel: 304, 316

SKUSO4-440-8
Thread Size440
Hole size in sheet (+0.003/-.0.000).166″
Minimum sheet thickness0.04″
Maximum sheet thickness.125″
Fastener material400 Stainless Steel
Minimum distance hole C/L to edge or bend.250″
When determining the distance between two or more fasteners, you can calculate the distance by the formula, C/L to edge + 1/2 the diameter of the second mounting hole. Example shown with x2 of the same hardware..313″
Recommended panel materialStainless Steel
Coating typePassivated
Length.250″
304 Stainless Steel material ranges0.048″-0.125″
316 Stainless Steel material ranges0.060″-0.125″