puddling-train

from The Century Dictionary.

• noun A set of two pairs of rolls in a rolling-mill. One pair, known as puddling-rolls, is used for consolidating the blooms after their removal from the hammer or the squeezer, and the second, known as mill-rolls, is used for rolling into bars the masses of iron as they come from the balling- or reheating-furnace, where they go from the puddling-rolls. See forge-train. Phillips and Bauerman, Elements of Metallurgy, p. 329.