Gordon B. Clarke
Banned
- Joined
- May 29, 2010
- Location
- Denmark
There are many that use the 3 wire method for measuring external thread pitch diameter. Many seem to make it more complicated than I think it can be. One of the reasons it’s a PITA is that most micrometers have a rotating spindle. If done at the machine make sure you have something to catch a dropped wire.
This is how I decided to do it long, long ago.
Place 2 wires on the top of the thread and hold them in place by resting the micrometer spindle on the 2 wires. That the micrometer spindle rotates becomes insignificant. Close the micrometer by pulling up the micrometer anvil until the 1 wire can be slid between the thread and the micrometer anvil. You turn the micrometer spindle until the single wire and the two wires are held in position and you have a measurement.
When the micrometer is “closed” you have the measurement result. After you’ve done it this way a few times you’ll probably never do it any other way. It applies to both three single thread wires and the type that “clip” onto the micrometer spindle and anvil.
One hand is holding the micrometer that is keeping the two wires down and your other hand is for the single wire.
This is how I decided to do it long, long ago.
Place 2 wires on the top of the thread and hold them in place by resting the micrometer spindle on the 2 wires. That the micrometer spindle rotates becomes insignificant. Close the micrometer by pulling up the micrometer anvil until the 1 wire can be slid between the thread and the micrometer anvil. You turn the micrometer spindle until the single wire and the two wires are held in position and you have a measurement.
When the micrometer is “closed” you have the measurement result. After you’ve done it this way a few times you’ll probably never do it any other way. It applies to both three single thread wires and the type that “clip” onto the micrometer spindle and anvil.
One hand is holding the micrometer that is keeping the two wires down and your other hand is for the single wire.
