Sheet metal bending offers numerous advantages. It allows for the creation of intricate and complex shapes, enabling the production of customized components and products. The process is highly efficient, enabling fast production times and cost-effective manufacturing. Additionally, sheet metal bending provides structural integrity and strength to the formed parts, making them suitable for a wide range of applications.

File Checklist

Follow this quick checklist to ensure high tolerance bent parts. Each of these will be elaborated on below.

Ensure minimum flange lengths are met
Ensure critical features fall outside of distortion zone
Exported as a 3D STEP file

Important:

Parts less than 3/16" in thickness will be bent with a 1mm(~0.039") radius.
Parts 3/16 or greater in thickness will be bent with a 4mm (~0.15") radius.
Use the chat bubble if you have any qestions about our process.

Material Table

See a full list of all bending materials and their capabilities.

Grade	Thickness	Min Flange Length 45°	Min Flange Length 90°	Min Flange Length 135°	Bend Radius
No items.

Bending Capabilities

While we do have capabilities that extend beyond this list, following these guidelines will ensure the fastest lead-time and highest quality parts. If you have a part that does not meet these guidelines, please reach out to support@fabworks.com and we will do our best to accommodate your needs.

Thin Materials (<0.187")

1-135 degree bends
1mm (~0.039") Radius
3:1:0.75 minimum ratio for small (<3") reverse bends
4:2:1 minimum ratio for large (>3") reverse bends

Ubends

Thick Materials (>0.187")

1-90 degree bends
4mm (~0.15") Radius
3:1.75:0.625 minimum ratio for small (<3") reverse bends
4:2:1 minimum ratio for large (>3") reverse bends

Ubends

Tolerances

Single bends will be held to a +/- .015" length tolerance
Single bends will be held to a +/- 1 degree angle tolerance
Features separated by multiple bends will be held to a additional +/- .015" for each separating bend
Die marks will be visible on all bends

K-factor

In sheet metal bending, the K-factor is a crucial parameter that determines the amount of material elongation and deformation during the bending process. It is a constant value used to calculate the bend allowance, which helps determine the final dimensions of the flat sheet before bending. The K-factor takes into account factors such as material thickness, bend radius, and material properties to accurately predict the amount of stretch that will occur on the inner and outer surfaces of the bend. Incorrect K-factor can lead to unexpected part dimensions after bending.

Bend Radius

The bend radius is the radius of the arc formed on the inside of the bend. It is a critical parameter that determines the minimum size of the bend. Its important to change this value in your CAD software before exporting your file. Incorrect bend radius values can result unexpected part dimensions after bending.

Note:

Parts less than 3/16" in thickness will be bent with a 1mm(~0.039") radius.
Parts 3/16" or greater in thickness will be bent with a 4mm (~0.15") radius.

Minimum Flange Lengths

The minimum flange length is the minimum length of the straight section of material between the bend and the edge of the sheet. It's crucial to check and meet the minimum flange length requirements specified for the material and thickness being used. Refer to the material table above for the minimum flange lengths for each material and thickness.

Flange Length Calculator

Use this handy calculator to get a more accurate estimate at the minimum allowed flange length for any arbitrary angle.

Note:

While this should give bendable values, its always best to set flange lengths above this range by atleast 1/16 for extra safety"

Bend angle must be between 1° and 135°

Distortion Zone

The distortion zone refers to the area of the sheet metal that experiences significant deformation and stretching during the bending process. It is important to identify and understand the distortion zone to ensure critical features, such as holes or slots, fall outside of this region. Placing critical features within the distortion zone can lead to dimensional inaccuracies or unwanted deformations, compromising the functionality and quality of the final part. Careful positioning of features outside the distortion zone is essential to maintain the integrity and accuracy of the bent sheet metal components.

Note:

To find the distance the distortion zone extends from the bend simply multiply the minimum flange length by 0.75.

The distortion zone extends out in both directions. It is NOT a single length centered on the bend line. Distortion Zone Graphic

Important:

Non critical dimensions can typically extend slightly into the distortion zone without issue. However these features will be subject to some warping and dimensional inaccuracy.

Do not hesitate to reach out to support@fabworks.com before placing your order if you have any questions.

Tube

Tolerances, kerf, taper and other guidelines for that are important to know when designing parts for our tube laser cutting service.

Hardware

Hardware insertion is the process of installing PEM nuts, studs, standoffs, and other fasteners into sheet metal parts. These components are essential for the assembly of sheet metal parts and are often used to attach other components like PCBs, panels, and other sheet metal parts.

Bending Guidelines