What is an Interference fit?
A fit where there is a negative allowance, resulting in a tight fit between parts
This type of fit is used when parts must be held together very securely.
Define Clearance fit.
A fit that has positive allowances, allowing for free movement between parts
This fit is used when parts need to move relative to each other.
What is a Transition fit?
A fit that has negative allowances but the total tolerances create exceed the allowance
This fit allows for a combination of tight and loose fits depending on the specific dimensions.
What is the significance of cooling the workpiece to room temperature before measuring?
It ensures accurate measurements
Temperature changes can affect the dimensions of the workpiece.
What is a Permanent Layout?
A layout used prior to machining that makes temporary scribed layouts visible after machining eg. prick punched layout
This method helps in maintaining accuracy during the machining process.
What is the purpose of the Keyseat Rule?
Used to scribe lines for key seats
It helps in creating precise lengthwise lines that are parallel to the axis of shaft.
How does Basic Layout differ from Semi-precision Layout?
Basic Layout is less accurate than Semi-precision Layout
Semi-precision layouts are used when higher accuracy is required.
What is Incremental Dimensioning?
A method that can result in accumulated errors
This approach adds dimensions sequentially, which can lead to inaccuracies.
Define Absolute Dimensioning.
Dimensioning that is done individually, results in NO accumulation error
This method specifies dimensions from a fixed point.
What is Limit Dimension?
A method where the maximum and minimum dimensions of a part are specified
This ensures that parts fit within a defined range.
What is an Allowance in machining?
The intentional difference between two mating parts at maximum material condition
This is crucial for ensuring proper fit between parts.
What does MMC stand for?
Maximum Material Condition
It is used to determine the allowance type of fit.
What is meant by Fit in machining?
The tightness or looseness between two mating parts
This is a critical factor in the assembly and function of mechanical components.
