A quiz : metallurgist?

we have a metal sheet and a hole in the middle of it . if we heat the sheet , the diameter of hole will be greater or smaller?

Anonymous2006-08-17T01:18:25Z

Favorite Answer

Smaller.

zahbudar2006-08-21T15:37:18Z

The hole will become larger because metal expands when you heat it. For example, if the metal sheet was a circle of 6 inches in diameter, when heated the metal might measure 6.025 inches in diameter. The hole in the center of the metal is of "X" diameter. When the metal expands the new hole diameter will be "X plus Y", where Y is the amount of expansion.

Consider that a common method of freeing rusted metal joints is to heat the larger and cool the smaller of the two. This creates a gap between the large, and the small one, permitting tools to be used to separate them.

Pigeon P2006-08-18T02:12:31Z

Ahh, the great conundrum.
When metal is heated it expands, thus the hole should be smaller, however, if you need to press fit a bearing onto a rod, you apply heat so the hole becomes bigger. So, which is it.
In industry, when you need to pressfit to pieces, lets say, press a steel pin into a hole, you heat the female side and freeze the male component. Thus, with the application of heat, the hole is bigger. It is hard to understand, however, the hole will, indeed get bigger. Just ask any machinist.

blackec20002006-08-23T18:56:03Z

It will get smaller. Think of it like cooking a donut. As the donut heats up it expands making the hole in the middle smaller. Metal expands as it heats up so the effect will be the same.

sandwreckoner2006-08-24T04:45:47Z

Initially the hole will expand. Because the metal material will expand from a solid state towards the liquid state. If you continue to heat it longer to the liquid state. The hole will start shrinking as the metal becomes a liquid.
Try it out and see.

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