Q: Do we need to calibrate the dial indicator after changing contact points?
- Unlike test indicators, you do not need to calibrate the dial indicator. The size, length or shape of the contact point has no effect on the indicator's accuracy. You will, of course, have to reset to zero but you would do this as a matter of course anyway.
Q: What information do I need in order to get the correct point?
- Contact points for dial indicators will either have inch or metric threads. With rare exceptions, these will be 4-48 or M2.5. That is, essentially, all you need to know.
Where you can find indicator contact points:
Q: How do I measure thread diameter?
- Using a micrometer or calipers, if the diameter over the threads is .112" then you have a 4-48 thread. If the diameter is .098" then you have the metric M2.5 thread (2.5 mm). Measure carefully since these two dimensions are fairly close together.