Bonus tolerance

Definition

Bonus tolerance is an additional allowance in geometric dimensioning and tolerancing that permits a part to deviate further from the specified limits when certain conditions are met, typically related to features of size. This concept enhances design flexibility and allows for better assembly of parts, as it helps in accommodating variations in manufacturing processes without compromising the function of the assembly.

5 Must Know Facts For Your Next Test

1. Bonus tolerance applies primarily to features of size, allowing parts to deviate from their nominal dimensions if certain criteria are met.
2. The amount of bonus tolerance is determined by the difference between the actual feature size and its specified size, enabling greater flexibility during manufacturing.
3. Bonus tolerance enhances the overall fit and function of assembled parts by compensating for manufacturing variability without requiring tighter tolerances.
4. This concept is particularly useful in applications where parts are produced using different methods or tools that may introduce variation.
5. Understanding bonus tolerance is crucial for engineers and designers to ensure that assemblies can function correctly even when individual parts vary within acceptable limits.

Review Questions

• How does bonus tolerance affect the design process and what advantages does it offer in terms of manufacturing flexibility?
  • Bonus tolerance impacts the design process by allowing designers to specify additional allowable variation for parts, especially those with features of size. This flexibility means that manufacturers can produce parts with more leeway in dimensions, reducing the likelihood of scrap or rework due to minor deviations. Consequently, this leads to cost savings and improved efficiency in production while still maintaining the quality and functionality of assembled components.
• In what scenarios would it be beneficial to apply bonus tolerance rather than traditional limit tolerances, and why?
  • Applying bonus tolerance is particularly beneficial in scenarios where multiple parts must fit together in an assembly but may be manufactured using different techniques or processes. For instance, if one part has a larger feature size than specified but is still within its bonus tolerance range, it can still fit with another component designed for a similar feature. This method reduces production constraints and allows for greater variability in manufacturing without compromising assembly integrity.
• Evaluate how the implementation of bonus tolerance might impact quality control processes in a manufacturing setting.
  • Implementing bonus tolerance can significantly alter quality control processes by allowing for broader acceptance criteria during inspections. Instead of focusing solely on traditional limit tolerances, quality control teams must assess whether the actual feature sizes meet both standard requirements and any applicable bonus allowances. This shift encourages a more holistic approach to evaluating part functionality and assembly capability, potentially leading to higher efficiency rates while still ensuring that all components perform as intended.

Related terms

Geometric Dimensioning and Tolerancing (GD&T): A system for defining engineering tolerances using symbols on technical drawings, which communicates information about the allowable variations in a part's geometry.

Feature of Size: A physical portion of a part or assembly that can be measured, such as holes or shafts, where bonus tolerance is often applied based on the size of these features.

Limit Tolerance: The total permissible variation of a dimension defined by its maximum and minimum limits, which establishes the range within which a feature must fall.