Datum Target Symbols

It can be impractical to use a datum to control the tolerance of an entire surface, as the datum establishes a theoretically exact plane, line, or profile. In order to specify practical data, relevant locations called datum targets can be selected and indicated on a drawing.

Symbol Description

Datum targets are circular frames divided in two parts by a horizontal line. The lower half is for a letter and a digit. The letter represents the datum feature, and the digit represents the datum target number. The upper half is for additional information, such as dimensions of the datum target area.

Types of the Symbol

You can attach datum targets to:

  • a point indicated by a cross
  • a line indicated by two crosses
  • an area indicated by a hatched area

AutoCAD Mechanical implements six types of datum target symbols depending on the termination types. They are:

None

Datum target without any termination.

Point

Datum target with a point termination.

Line

Datum target with a line termination.

Circle

Datum target with a circular termination.

Rectangle

Datum target with a rectangular termination.

Attached

Datum target attached to another datum target.

Symbol Standard

You use the Datum Target Settings dialog box to set the appearance of the symbol. Available options conform to the current International Drafting Standard.

When saving into AutoCAD R12 format, the program does not save the hatch pattern in the circle or rectangle datum target. To work around this functionality, explode the symbol before saving as R12.

Supported Drafting Standards

  • ASME Y14.5M (1994)
  • BS 308 Part 3 (1990)
  • CSN 01 3138 (1994)
  • GB/T 1182 (1996)
  • ISO 1101 (1983)
  • ISO 7083 (1993)
  • JIS B 0021 (1984)

Procedures
To create a datum target symbol

The program can create six types of datum target symbols in the drawing.

To create the basic type - the datum target symbol with no termination use the following method:

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select None.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify the start point of the leader.
  5. Specify one or more points for the leader vertices, and press ENTER.
  6. In the Datum Target dialog box, enter the data for the datum target.
  7. Click OK.
Datum target with a point termination

This type of datum target symbol terminates with a cross indicating the target point.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Point.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify a point for the point termination.
  5. Specify one or more points for the leader vertices, and press ENTER.
  6. In the Datum Target dialog box, enter the data for the datum target.
  7. Click OK.
Datum target with a line termination

This type of datum target symbol terminates with a line indicating the target line. A cross shows the start and the endpoint.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Line.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify a point for the start point of the line termination.
  5. In the drawing area, specify a point for the endpoint of the line termination. The program draws a line to indicate that the target region lies along an edge between the two Xs. The leader start point is at the midpoint of the target line.
  6. Specify one or more points for the leader vertices, and press ENTER.
  7. In the Datum Target dialog box, enter the data for the datum target.
  8. Click OK.
Datum target with a circular termination

This type of datum target symbol ends in a target circle.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Circle.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify a point for the center of the circle termination.
  5. Specify the radius of the circular termination by entering a value or by dragging the circle to the correct size. You can also enter d for the Diameter option, and enter a value, or select the diameter on the screen.
  6. Specify one or more points for the leader vertices, and press ENTER.
  7. In the Datum Target dialog box, enter the data for the datum target.
  8. Click OK.
Note
  • The real radius of the target circle can be used as the Dimension parameter of the datum target symbol. Under Dimension enter the string “<>”. When you use grip points to change the radius of the target circle, the program refreshes the Dimension value automatically.
  • You can change the type of the boundary line and the hatching pattern in the Datum Target Properties dialog box.
Datum target with a rectangular termination

This type of datum target symbol end in a target rectangle.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Rectangle.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify a point for the center of the rectangle termination.
  5. Specify the corner or edge of the rectangle.
  6. Specify one or more points for the leader vertices, and press ENTER. The leader start point is at one of the corners. As you move the pointer, the leader start point moves from one corner to the next. When you are pointing to the corner that you want, select the second point.
  7. In the Datum Target dialog box, enter the data for the datum target.
  8. Click OK.
Note
  • The real dimensions of the target rectangle can be used as the Dimension parameter of the datum target symbol. Under Dimension enter the string “<>”. When you use grip points to change the shape of the target rectangle, the program refreshes the Dimension value automatically.
  • You can change the type of the boundary line and the hatching pattern in the Datum Target Properties dialog box.
Datum target attached to another datum target

Using the following method you create two or more datum targets attached to one leader.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Attached to Another.
  3. In the drawing area, select a datum target symbol to attach the new symbol to. The pick point controls the position where the program connects the datum target.
  4. In the Datum Target dialog box, enter the data for the datum target.
  5. Click OK.
To create a datum target with a point termination

This type of datum target symbol terminates with a cross indicating the target point.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Point.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify a point for the point termination.
  5. Specify one or more points for the leader vertices, and press ENTER.
  6. In the Datum Target dialog box, enter the data for the datum target.
  7. Click OK.
To create a datum target with a line termination

This type of datum target symbol terminates with a line indicating the target line. A cross shows the start and the endpoint.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Line.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify a point for the start point of the line termination.
  5. In the drawing area, specify a point for the endpoint of the line termination. The program draws a line to indicate that the target region lies along an edge between the two Xs. The leader start point is at the midpoint of the target line.
  6. Specify one or more points for the leader vertices, and press ENTER.
  7. In the Datum Target dialog box, enter the data for the datum target.
  8. Click OK.
To create a datum target with a circular termination

This type of datum target symbol ends in a target circle.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Circle.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify a point for the center of the circle termination.
  5. Specify the radius of the circular termination by entering a value or by dragging the circle to the correct size. You can also enter d for the Diameter option, and enter a value, or select the diameter on the screen.
  6. Specify one or more points for the leader vertices, and press ENTER.
  7. In the Datum Target dialog box, enter the data for the datum target.
  8. Click OK.
Note
  • The real radius of the target circle can be used as the Dimension parameter of the datum target symbol. Under Dimension enter the string “<>”. When you use grip points to change the radius of the target circle, the program refreshes the Dimension value automatically.
  • You can change the type of the boundary line and the hatching pattern in the Datum Target Properties dialog box.
To create a datum target with a rectangular termination

This type of datum target symbol end in a target rectangle.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Rectangle.
  3. Select an object to attach the datum target to.
  4. In the drawing area, specify a point for the center of the rectangle termination.
  5. Specify the corner or edge of the rectangle.
  6. Specify one or more points for the leader vertices, and press ENTER. The leader start point is at one of the corners. As you move the pointer, the leader start point moves from one corner to the next. When you are pointing to the corner that you want, select the second point.
  7. In the Datum Target dialog box, enter the data for the datum target.
  8. Click OK.
Note
  • The real dimensions of the target rectangle can be used as the Dimension parameter of the datum target symbol. Under Dimension enter the string “<>”. When you use grip points to change the shape of the target rectangle, the program refreshes the Dimension value automatically.
  • You can change the type of the boundary line and the hatching pattern in the Datum Target Properties dialog box.
To create a datum target attached to another datum target

Using the following method you create two or more datum targets attached to one leader.

  1. Click Annotate tab Symbol panel Datum Target. At the Command prompt, enter AMDATUMTGT.
  2. In the Termination Type dialog box, select Attached to Another.
  3. In the drawing area, select a datum target symbol to attach the new symbol to. The pick point controls the position where the program connects the datum target.
  4. In the Datum Target dialog box, enter the data for the datum target.
  5. Click OK.
To edit a datum target symbol

  1. In the drawing area, double-click the datum target symbol to edit.
  2. In the Datum Target dialog box, perform the changes.
  3. Click OK.
Tip
  • Dimension parameter: The real radius of the target circle, or the real dimensions of the target rectangle can be used as the Dimension parameter of the datum target symbol. Under Dimension, enter the string “<>”. When you use grip points to change the dimensions of the target area, the program refreshes the Dimension value automatically.
  • Target areas: You can change the boundary line type and the hatching pattern for the target areas in the Datum Target Properties dialog box.
To change the leader line and the arrowhead
  1. In the drawing area, double-click the datum target symbol to edit.
  2. In the Datum Target dialog box, select the Leader and Text tab.
  3. Under Linetype, select the leader line type.
  4. From the Arrowhead drop-down list, select an arrowhead.
  5. In the Datum Target dialog box, click OK.
Note
To attach and detach a datum target symbol

The symbol can exist as a free-standing object or you can attach it to an object in the drawing. Every symbol leader can attach to only one object in the drawing. The attached symbol keeps the offset with the object when you move it. If a symbol leader is attached to an object and you want to attach it to another object, detach it first.

  1. In the drawing area, double-click the datum target symbol to edit.
  2. In the Datum Target dialog box, choose Attach.
  3. Select an object in the drawing to attach the datum target.
  4. In the Datum Target dialog box, click OK.
Tip
  • To detach the symbol, in the Datum Target dialog box choose Detach.
  • The program can attach the datum target symbol when you create it.
To set the standard properties for datum target symbols

You can access the Datum Target Properties dialog box from the Datum Target dialog box.

  1. Choose the Properties button to display the Datum Target Properties dialog box.
  2. Use the dialog box options to control the properties for the datum target symbols.
  3. Click OK to close the Datum Target Properties dialog box.
To configure the master settings for leaders
  1. At the Command prompt, enter AMOPTIONS.
  2. In the Options dialog box, click the AM:Standards tab.
  3. In the Standard Elements list, double-click the root node (the standard name). The Standard Settings dialog box appears.
  4. To change the arrowhead shape, in the Arrowhead list, select the arrowhead.
  5. To change the arrow size, in the Arrow size list, select the size.
  6. To change the leader color, in the leader section, in the color list, select the color.
  7. Click OK until all dialog boxes close.
To link text and leader master settings to dimension styles
  1. At the Command prompt, enter AMOPTIONS.
  2. In the Options dialog box, click the AM:Standards tab.
  3. In the Standard Elements list, double-click the root node (the standard name). The Standard Settings dialog box appears.
  4. Select the Link to dimension style check box.
  5. To link to the Leader substyle only, select the Link to leader dimension style only check box.
    NoteIf you clear the Link to leader dimension style only check box, the leader and text settings link to the base dimension style. If you modify text or leader settings, all dimension substyles update unless the substyle overrides the setting.
  6. In the Style list, select the dimension style to link to.
  7. Click OK until all dialog boxes close.
To detach a symbol from an object
  1. In the drawing area, double-click the symbol to edit.
  2. Click Detach.
    NoteThe Detach button is available only if the symbol is attached to an object.
  3. Click OK.
Commands
AMDATUMTGT

Creates a datum target symbol and attaches it to an object in the drawing area.

 Ribbon: Home tab Annotate panel Symbol drop-down Datum Target. Not available on the ribbon in the current workspace.
 Toolbar: Symbols
 Menu: Annotate Symbols Datum TargetDoes not exist in the menu in the current workspace.
 Command entry: amdatumtgt

You can specify the type of termination to use for the target point and assign up to 4 characters to identify the datum feature.

COMMAND LINE OPTIONS

Termination type: In the Termination Type dialog box select a termination for the datum target. Follow the command prompts to create the selected datum target termination.

Select object to attach: Select an object in the drawing to attach the symbol. If you do not want to attach the symbol, select a start point of the leader.

In this case the following prompt does not appear.

Start Point: Specify the start point of the leader.

Next Point <Symbol>: Specify the next vertex of the leader or press ENTER to place the symbol.

COMMAND LINE DEFINITIONS

Symbol

Places the symbol in the drawing

DIALOG BOX DEFINITIONS

Termination Type dialog box

Select a termination type for the datum target symbol.

The termination types are:

  • None: Datum target without any termination.
  • Point: Datum target with a point termination.
  • Line: Datum target with a line termination.
  • Circle: Datum target with a circular termination.
  • Rectangle: Datum target with a rectangular termination.
  • Attached: Datum target attached to another datum target.

Datum Target dialog box

Symbol tab

 

Options

   

Datum area on far side

Changes the leader linetype to dashed, indicating that the datum target is on the far side.

 

Requirements

   

Dimension

Specifies the size of the datum area.

   

Datum

Specifies a label to identify the datum. You can specify a datum reference letter and a target number of up to 3 digits.

Leader and Text tab

 

Arrowhead

Specifies the type of the leader arrowhead. The setting By Standard acquires the arrowhead from the current drafting standard. If you change the arrowhead selected for the current drafting standard (in the Standard Settings dialog box.or Datum Target Settings dialog box.) the arrowhead for this symbol updates automatically.

 

Edit object attachment

   

Attach

Attaches the symbol to a geometry in the drawing.

   

Detach

Detaches the symbol. The symbol becomes a free-standing object.

Settings

Opens the Datum Target Settings dialog box and enables you to edit the default settings for the current drafting standard.

Datum Target Settings dialog box

Use the Datum Target Settings dialog box to configure the default settings of datum target symbols for the current standard.

Revision

Displays most recent revision of the standard this symbol complies with.

Style

 

Target point size

Sets the size of the target point for datum targets with point terminations. The value you set refers to half the width of the “X” the target point.

 

Area hatch distance

Sets the distance between hatch lines for datum targets with rectangular and circular terminations.

 

Hatch angle

Sets the hatch angle for datum targets with rectangular and circular terminations.

 

Boundary linetype

Specifies the linetype to use for the datum target boundary for datum targets with rectangular and circular terminations.

Leader

 

Hidden linetype

Specifies the linetype to use for the leader of datum target symbols that indicate that the datum target is on the far side.

 

Draw arrowhead for point termination

Specifies whether arrowheads are drawn for datum targets with point terminations. This setting has no affect on datum target symbols that already exist in a drawing. It only affects new symbols you create.

 

Arrowhead

Specifies the type of the leader arrowhead. When the arrowhead is set to ByNameOfCurrentDraftingStandard, it acquires the arrowhead from the master settings of the current drafting standard. If the master setting changes, the arrowheads for all datum target symbols that are set to ByNameOfCurrentDraftingStandard, change automatically.

 

Arrow size

Specifies the size of the leader arrowhead. When the arrow size is set to ByNameOfCurrentDraftingStandard, it acquires the arrow size from the master settings of the current drafting standard. If the master setting changes, the arrow size for all datum target symbols based on the current drafting standard change automatically.

 

Color

Specifies the color of the leader. When the leader color is set to ByNameOfCurrentDraftingStandard, it acquires the color from the master settings of the current drafting standard. If the master setting changes, the leader color of all datum target symbols based on the current drafting standard change automatically.

Text

 

Height

Specifies the text height for symbol text. When the height is set to ByNameOfCurrentDraftingStandard, it acquires the text height from the master settings of the current drafting standard. If the master setting changes, the text height of all datum target symbols based on the current drafting standard change automatically.

If the current standard is a custom standard, you can specify a non-standard text height. If not, the AutoCAD Mechanical restricts you to selecting a value from the list.

 

Color

Specifies the color of symbol text. When the text color is set to ByNameOfCurrentDraftingStandard, it acquires the color from the master settings of the current drafting standard. If the master setting changes, the text color of all datum target symbols based on the current drafting standard change automatically.

NoteIf the text height changes, the color automatically changes to the default color corresponding to that text height. Text object colors are set from the Object Property Settings dialog box.

Restore Defaults

Returns all values to the default values for the current standard.