How to Use the SOLIDWORKS Flex Feature

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The SOLIDWORKS Flex feature lets you bend, twist, taper, or stretch solid geometry. It is useful for concept modeling, ergonomic shapes, packaging forms, rubber-like parts, and quick design studies where building the shape feature by feature would take too long.

Flex is powerful, but it can also create geometry that is hard to manufacture or edit later. Use it deliberately and keep the original design intent in mind.

SOLIDWORKS Flex feature example — The Flex feature can bend, twist, taper, or stretch an existing body.

Open the Flex feature

Open the part you want to modify.
Go to Insert > Features > Flex.
Select the body or bodies to flex.
Choose the flex type: Bending, Twisting, Tapering, or Stretching.
Adjust the triad and trim planes.
Preview the result before accepting the feature.

Opening the Flex feature in SOLIDWORKS — Flex is found from Insert > Features > Flex.

Choose the right flex type

Bending: bends the selected body around an axis.
Twisting: rotates geometry along the flex region.
Tapering: narrows or widens geometry across the selected region.
Stretching: lengthens or compresses the selected region.

Start with the smallest change that communicates the shape. Extreme values can cause self-intersections or messy downstream edits.

SOLIDWORKS Flex type controls — The four flex types are useful for different shape changes.

Position the triad and trim planes

The triad controls the flex direction and orientation. The trim planes define the region affected by the feature. Drag or rotate them until the preview matches the intended shape. If the wrong part of the model changes, move the trim planes before changing the flex value.

SOLIDWORKS Flex triad and trim planes — The triad and trim planes control where and how the flex is applied.

Preview and rebuild carefully

After changing flex settings, inspect the preview from several angles. Look for folded faces, thin slivers, self-intersections, or unexpected deformation. If the model is used in an assembly, check fit after the feature rebuilds.

Previewing a SOLIDWORKS Flex feature — Inspect the preview before accepting the feature.

When Flex is a good choice

Flex is useful when you need a quick deformation or organic-looking change. It is less ideal when the part needs strict manufacturing dimensions controlled by simple sketches and features. If the part must be machined or inspected tightly, consider using normal sketches, sweeps, lofts, or surface tools instead.

For related shaping tools, see how to use the SOLIDWORKS Freeform tool and how to use Lofted Boss/Base in SOLIDWORKS.

Finished SOLIDWORKS Flex feature — Use Flex for controlled deformation, then verify the final shape.

Common Flex problems

The model fails to rebuild: reduce the flex value or move the trim planes.
The wrong region changes: reposition the trim planes before editing the flex amount.
The body twists unexpectedly: rotate the triad and preview again.
The part becomes hard to dimension: use conventional features for manufacturing-critical geometry.

Reference: SOLIDWORKS Help lists Flex types including bending, twisting, tapering, and stretching, with triad and trim-plane controls for the deformation region.