How to Add Tolerance to Dimension in AutoCAD?

Understanding Tolerances in AutoCAD

Adding tolerances to dimensions in AutoCAD is essential for ensuring that parts will fit together correctly during production. A tolerance indicates the permissible variation from a specified measurement and is crucial for quality control in design and manufacturing. Here’s a detailed guide on how to effectively add tolerances to your dimensions in AutoCAD.

Steps to Add Tolerance to Dimension in AutoCAD

Step 1: Open the Tolerance Tool

1. Launch your AutoCAD application and open the drawing you wish to edit.
2. Navigate to the Annotate tab located in the main toolbar.
3. From the Dimensions panel, click on the Tolerance button to open the Tolerance dialog box.

Step 2: Selecting the Tolerance Type

1. In the Tolerance dialog, locate the first square under the Sym panel.
2. Click on this square to bring up a list of available tolerance symbols.
3. Choose the appropriate symbol that represents the desired tolerance type for your dimension.

Step 3: Inputting Tolerance Values

1. Under the Tolerance 1 section, click the designated box to insert a diameter symbol if necessary.
2. In the Text box, type in the first tolerance value that you want to apply (e.g., ±0.10).
3. If you are using different tolerances, remember to adjust them accordingly in each respective box.

Step 4: Adjusting Tolerance Variables

1. If you need to add specific tolerances, ensure that your DIMTOL system variable is set to 1 to enable the display of the tolerances in your dimensions.
2. You can set symmetrical tolerances by entering a value in the Upper Value field. This creates a plus/minus tolerance that is uniformly applied.

Modifying Dimension Accuracy

When precision is key, taking the time to adjust dimension accuracy is necessary. Follow these steps:

1. Select the dimensions you wish to modify within your drawing.
2. Go to the Power Dimensioning tab on the toolbar.
3. Look for the Dim Text panel and find the section for Primary Precision. Here, specify the number of decimal places you want your dimensions to be rounded off to.

Understanding Different Types of Tolerances

Tolerances come in various types that can be applied depending on the specifications of your design:

• Limit Dimensions: Provide two limit values to specify the upper and lower bounds of a dimension.
• Unilateral Tolerances: Allow variation in only one direction from the nominal dimension.
• Bilateral Tolerances: Allow variation in both directions from the nominal dimension.

FAQs

1. What is the purpose of adding tolerances to dimensions?
Adding tolerances ensures that manufactured parts comply with design specifications, facilitating correct assembly and function in the final product. It helps prevent defects that can result from dimensional inaccuracies.

2. How can I visualize tolerances in my drawing?
Tolerances can be visualized through various symbols and annotations directly in the AutoCAD workspace. Make sure to select and apply the appropriate symbols during the tolerance addition process to convey the information clearly.

3. Can I customize tolerance symbols in AutoCAD?
Yes, AutoCAD allows users to customize tolerance symbols. You can create your symbols by modifying existing ones or designing new ones to fit your specific project requirements through the Tolerance dialog settings.