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Flat Head Spike, Central Pacific Railroad, original construction, 1868

Report of testing of another spike recovered with the spike shown above to verify that was wrought iron:

December 15, 2002
Test performed on railroad spike, on December 2nd, 2002, to determine if it was fabricated of "wrought iron". Wrought Iron Test - Bent SpikeTest performed by W. W. Curry for G.J. Graves in the Marshall Gold Discovery Park original blacksmith shop. The procedure I used to establish the type of ferrous material used in this spike was one I have used over the years a number of times when the makeup of the ferrous item was in question. I first heated this spike to approximately 2100 degrees F., as determined by the incandescent color we use to estimate approx. temperatures. Then I simply bent it 180 degrees, back on itself, in a tight bend using my hammer on an anvil. Instead of smoothly bending, this material cracked open at the bend, revealing it's fibrous content. My experience has been that the more modern steel products will not crack under the same conditions, but rather make the same type of bend but without any cracking. It is my understanding that cold bending wrought iron, after notching it with a cold chisel will also show up the fibrous nature of wrought iron. I don't have enough experience using this test to feel comfortable relying on it as an absolute test. The fibrous material contained in wrought iron is a siliceous slag that could vary in content by weight from 1 to 3%. I hope this test description will be of some use to you. Wrought iron test performed by W. R. Curry Test report prepared by him and signed on the above date.

Courtesy Bruce C. Cooper Collection and G.J "Chris" Graves.


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