What causes Galling??? 1

Galling is basically the bonding of the one surface to another. This normally occurs when the surfaces are under load together. When the surfaces move, pieces of the surface break away at some other position other than the original surface. To summarise galling occurs.

If you need more info there are many books and papers. Look under the topic of Tribology or surface wear.

Hope this helps

Anthony

To quote Mr. Tony Sofronas of ExxonMobil Chemical Co. from an article in Hydrocarbon Processing / June 2001.
Case 3: Shaft galling in a bushing
"Galling is a sort of welding of one part to another. For it to occur there usually has to be sufficient force along with materials that are susceptable to galling. Lack of lubrication increases the tendency to gall."
There is a table in the article that I have summarized as follows...Soft metals on soft metals likely to gall. Hard metals against soft metals, possible. Hard metals against hard metals, not likely.