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The Symmetric Lifting Eye is a flat lifting lug: a straight base edge, two straight sides that rise from the ends of the base and run tangent into a round head, and a round hole through the head for a shackle pin or hook. The part is symmetric about the vertical centre line of the base. It is welded to a structure along its base edge to give a lifting point. The shape has no older (alias) names.

It appears in the shapes library under Lifting Lugs, Triangles and Tools. For a lug with one vertical side see the Right-Angle Lifting Eye; for a lug with a rectangular body see the Square Lifting Lug.

Insert point and direction

The insert point (Base X, Base Y) is the left-hand end of the base edge. The base runs along +X from the insert point for the Base Width, and the eye is built upward, in +Y. The centre of the hole is at half the Base Width along X and at the Eye Height above the base.

The outside profile is one closed path that starts at the insert point and runs anticlockwise: along the base to the right-hand end, up the right side to its tangent point on the head, over the top of the head on an arc of radius Eye Diameter / 2 + Eye Thickness, and down the left side back to the insert point. The hole is a separate full circle. Use Rotation (see Transform) to point the eye in another direction.

The Base Width dimension is drawn along the base edge. The Eye Height dimension is drawn vertically from the base line to the centre of the hole. The Eye Thickness dimension is drawn above the hole, from the edge of the hole to the outside of the head. The Eye Diameter dimension is a radial dimension: it runs from the centre of the hole to its edge, and its label is the hole diameter, shown with the diameter symbol (ø).

Properties

Lengths are in the current units (mm or inch). The table follows the order of the property page. The defaults are for a new shape in millimetres; in inches they are 5 in, 3 in, 2 in and 1 in.

Limits

•The four values are not range-checked and not checked against each other when they are changed. Enter all four as positive values. With an Eye Diameter of 0 the hole is drawn as a point, not a circle, and the head radius is Eye Thickness alone. Use a value greater than 0.

•If the Base Width is less than the head diameter (Eye Diameter + 2 × Eye Thickness), the shape still builds, but the sides lean outward from the base to the head instead of inward.

•Nothing stops the head from reaching the base. If the Eye Height is less than Eye Diameter / 2 + Eye Thickness, the head drops below the base line; if it is less than Eye Diameter / 2, the hole breaks through the base edge. Check the drawing before cutting.

•With an Eye Thickness of 0 the hole is the outside edge of the head and leaves no material over the top.

When the outline cannot be built

Each side is a straight line from an end of the base that just touches the head circle (radius Eye Diameter / 2 + Eye Thickness, centred on the hole). No such line exists when an end of the base is on or inside the head circle, that is when (Base Width / 2)² + Eye Height² ≤ (Eye Diameter / 2 + Eye Thickness)². In that case the outside profile is not drawn and only the hole is. This is typical of a narrow base with a low, large eye. To fix it, increase the Eye Height or the Base Width, or reduce the Eye Diameter or the Eye Thickness.

The red banner Warning: Cannot build shape from these parameters on the property page is shown only when the build raises an error internally. The missing-outline case above may occur without the banner, so check the drawing for the outline rather than relying on the banner.

Every 2D shape also has the Transform properties (Base X, Base Y, Rotation, Scale, Mirroring X) and the Polar Array properties, listed after the shape's own properties.