What does flatness mean in GD?
What does flatness mean in GD?
Flatness is a GD form tolerance that is conceptually simple. According to the ASME Y14. 5 standard, it “specifies a tolerance zone defined by two parallel planes within which the surface must lie.”
How do you define straightness?
/ˈstreɪtnəs/ [uncountable] the fact of being without bends or curves; the fact of going in one direction only. the straightness of her hair.
How is flatness defined?
Flatness is a measure of a surface’s form compared against itself, indicating that all the points along the surface lie in the same plane. Symbolized in GD by a parallelogram, flatness allows you to limit waviness or variation in a surface without tightening its dimensional tolerance.
What is difference between flatness and parallelism?
Flatness – The condition of a surface having all elements in one plane. Parallelism – The condition of a surface, line, or axis which is equidistant at all from a datum plane or axis.
How is straightness measured?
Using a Height Gauge Secure the target so that the height is evenly matched on the left and right, using small jacks in order to prevent the target from tilting. Move the target or the height gauge straight to measure the straightness. The difference between the maximum and minimum values (△H) is the straightness.
How is GD flatness calculated?
Place the target on the precision plane table and secure it in place. Set the dial gauge so that its measuring part comes into contact with the measurement surface. Move the target so that the measurement surface is evenly measured, and read the dial gauge values. The largest deviation value is the flatness.
How do you determine straightness and flatness?
1. Flatness is a property of a plane, while the straightness is about a straight line that only has length….Measuring straightness can identify any warpage in long objects or workpieces.
- Use a Coordinate Measuring Machine (CMM)
- Use a Height Gauge.
- Straightness measuring instrument.
What is flatness in metrology?
Flatness is the 3D equivalent of the surface straightness control. While straightness has parallel lines representing its tolerance zone, the flatness tolerance zone is formed by two parallel planes.
Which method is used to test the straightness?
Explanation: Straight edge is a measuring tool consist of a steel and is used to check the straightness. Straight edges are used in machining industry and automotive service.
What is profile in GD?
The profile of a surface specification defines a 3-dimensional tolerance zone equidistant from the theoretically exact shape or curve (i.e. the “True Profile”) to control all the points along the surface to be within a tolerance range.
