Hi Tash, how much iron do you believe is needed to make a winch? Anyway here is a site and excerpt about ancient iron usage.


http://www.vanderkrogt.net/elements/elem/fe.html [

Although Iron occurs only sparingly in the free state, the abundance of ores from which it may be readily obtained led to its use in a very remote period. Iron has been known and used since prehistoric times. The writings of the most early civilizations refer to it, and there is evidence that it was known more than 7000 years ago; in China the usage of steel goes back to 2550 B.C. Some vedic poets wrote that their prehistoric ancestors already knew iron and were able to transform it into utensils through a considerable range of technics.


So the PBS site is probably right in suggesting iron as winches.

The amount of Iron needed for a winch would depend on the style, size of the winch and weight of the block. i would think not much iron would be lying around the Giza plateu. anyway if they had made iron winches. why not use iron tools? it is quite possible they traded, around 1000BCE there were batterys containing iron found in a tomb near Modern day baghdad.
http://www.unmuseum.org/bbattery.htm (just for a point of interest.)

well, i also said 'not enough iron for what they would have needed to quarry the stones' because there was either no iron or little of it.