Why surface plates are used for marking?

Question

Question

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ALP CBT 2 Fitter Previous Paper: Held on 21 Jan 2019 Shift 1

Answer 1

Explanation:

A surface plate is used to test the flatness of other surfaces or to provide a truly flat datum surface in marking off work for machining.
The flat surface provides stability.
It is also used for the inspection of gauges, jigs, and fixtures.
Surface plates are generally made of good quality cast iron which is stress-relieved to prevent distortion.
In order to retain its flatness, a surface pate must be treated with extreme care:
- Always clean a surface plate with a soft dry cloth before use and cover it after use.
- Slide heavy objects onto a surface plate rather than lowering them
- Never hammer anything on a surface plate.