Shackle

After clicking , the following dialog displays:

To define a bar, the following should be specified:

Bar diameter (the diameter defined in the dialog is adopted by default)
Cover of reinforcing bars (the cover defined in the dialog is adopted by default)
In the Parameters of reinforcing bar shape field - anchor parameters for reinforcing bar ends, i.e. hook angle and length; you can lock a hook length by selecting the option next to the edit field for defining a hook length ( appears). The edit field becomes inaccessible. If you modify parameters (length or diameter) of a bar with locked hook length, the hook length does not change.

Standard hook angle values include:

The following icons are available while a shackle is being defined (the remaining icons are unavailable):

Points - is used to indicate directly two points located on a contour edge. After selecting, the dialog closes, and the cursor assumes the shape of a cross (see the ACAD command ‘line’). After defining the first point determining the bar position, bar length changes dynamically depending on the cursor position.
Bar location depends on a direction of point definition. The principle that holds when defining reinforcement consists in determining the order of points clockwise (along the EXTERNAL part of an object). The defined bar will always be positioned in the inner part of an object. In the case of bar with hooks of a bending angle greater than zero degrees, the hooks will always be located on the side opposite to the side where points defining the bar length are placed, thus they will be turned towards the middle of an object.

Command line identical as for pin
Bars - is used to define the existing point reinforcement (point reinforcement, i.e. presentation of longitudinal reinforcement within a cross section). After clicking this icon, the dialog closes, and the cursor assumes the shape of a cross (see the ACAD command ‘polyline’). Once a bar is indicated, the position of the bar with hooks is shown dynamically. A bar definition is completed when another point reinforcement bar is indicated. In this case, a cover value is not considered.
Command line:

Side.

A definition of a bar shape is ALWAYS completed at the moment a second point in the form of a point reinforcement bar, is indicated.