:)

http://www.google.com/search?q=redondo round bar&ie=utf-8&oe...
http://www.google.com/search?q=redondo round bar&ie=utf-8&oe...

Probably a small mill for rolling round steel bars

http://www.ovako.com/index.asp?r=510

I used to translate for the steel industry in Sheffield many years ago, and from my memory this would be the most probable meaning.

or "rebar rolling". The original is not really specific enough, but I am quite confident that it means this because I do not see any other use of "bar" in construction that would use a full-fledged "tren de laminación".

There are possible variations on this (concrete bar", "ribbed concrete bar"... This last is really specific and most used -and standardized. This translates as "barra corrugada para construcción", but I do not see "corrugada" in the original)

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Note added at 36 minutos (2011-09-08 17:37:31 GMT)
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Well, I meant steel bars for concrete reinforcing. "palanquilla" ("billet") is a steel profile of square section which is (normally) an intermediate state within the rolling process ("semiproducto"). The way I see it, the matter here is that:

(1) the only application for "bars" in the building industry that requires, in itself, a rolling mill is this one: Rebar making.

(2) In this particular case (no doubt to increase added value, and to diversify), instead of buying an intermediate product ("palanquilla" from a steel mill, they decided to integrate their process vertically and go all the way up to make their own steel (and, possibly, to make other rolled products)