.. _bpy.types.ScrewModifier:

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Screw Modifier
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The Screw Modifier is similar to the *Screw tool* in the *Tool Shelf*
in that it takes a profile object, a Mesh or a Curve, to create a helix-like shape.

.. figure:: /images/modeling_modifiers_generate_screw_align.png
   :width: 540px

   Properly aligning the profile object is important.

The profile should be properly aligned to the cardinal direction of the object rather than to the screw axis.


Options
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.. figure:: /images/modeling_modifiers_generate_screw_panel.png

   Screw Modifier.

Axis
   The axis along which the helix will be built.

   Screw
      The height of one helix iteration.
Axis Object
   The name of an object to define the axis direction.

   Object Screw
      Use the distance from the *Axis Object* to define the height of one helix iteration.
Angle
   Degrees for a single helix revolution.
Steps
   Number of steps used for a single revolution displayed in the 3D View. Beware of setting this higher than
   *Render Steps*, which is the value used for rendering.
Render Steps
   As above, but used during render time. Increase to improve quality.
Smooth Shading
   Output faces with smooth shading rather than flat shading.
   The smooth/flat shading of the input geometry is not preserved.
Calculation Order
   Order of edges is calculated to avoid problems with normals and shading. Only needed for meshes, not curves.
Flip
   Flip normals direction.
Iterations
   Number of revolutions.
Stretch U/V
   Stretch the UV coordinates from (0.0 to 1.0) when UVs are present.
Merge Vertices
   Merge vertices that lie on the axis of rotation.
   Use this to close off end points with a triangle fan.
Merge Distance
   Vertices under this distance to the axis are merged.