gen-define-tolerance-and-fit-in-machining-and-give-one-short-wor-2a7c

Define tolerance and fit in machining and give one short worked example.

# Tolerance and Fit in Machining ## Definitions **Tolerance**: The permissible variation in the dimension of a part. It's the difference between the maximum and minimum allowable sizes. **Fit**: The degree of tightness or looseness between two mating parts (typically a hole and shaft). It determines how parts assemble and function together. ## Types of Fits - **Clearance fit**: Hole is always larger than shaft (parts move freely) - **Interference fit**: Shaft is always larger than hole (parts pressed together) - **Transition fit**: May have slight clearance or interference --- ## Worked Example **Problem**: A shaft must fit into a bearing hole with the following specifications: - Hole: Ø25.00 mm with tolerance of +0.02/-0.00 mm - Shaft: Ø24.96 mm with tolerance of +0.00/-0.02 mm **Solution**: **Hole dimensions:** - Maximum = 25.00 + 0.02 = **25.02 mm** - Minimum = 25.00 - 0.00 = **25.00 mm** - Tolerance = 25.02 - 25.00 = **0.02 mm** **Shaft dimensions:** - Maximum = 24.96 + 0.00 = **24.96 mm** - Minimum = 24.96 - 0.02 = **24.94 mm** - Tolerance = 24.96 - 24.94 = **0.02 mm** **Fit analysis:** - Maximum clearance = 25.02 - 24.94 = **0.08 mm** - Minimum clearance = 25.00 - 24.96 = **0.04 mm** **Result**: This is a **clearance fit** with clearance ranging from 0.04 to 0.08 mm, allowing free rotation.