The method of iron production in a pit furnace as its processing in the conditions of ancient forging shop were primitive only at the first glance.

It was certainly very time-consuming and of low efficiency, it was also difficult to control the ingredients of the obtained metal because of its doughy and not liquid consistency. It does not mean that it was impossible to obtain iron of excellent parameters and many iron objects made in those days are worth admiration owing to their perfect handiwork. Ancient blacksmiths could regulate the quality of iron very well though it required great experience and frequently great work load and a lot of time. By forging iron many times and welding it again it was possible not only to change its chemical constitution but also to acquire such qualities of iron that cannot be found in contemporary industrial steel production. A sword made of such iron forged and welded repeatedly is much more resistant to strikes and breakings than a sword forged from a homogeneous piece, even of a very good quality contemporary steel.

The best example of the possibility to obtain an excellent quality of pit furnace iron by means of smith's methods is the fact that still today this type of iron is made in small amounts and it reaches very high prices.

It is this method that is used to obtain iron for the production if the best, unique Japanese swords (katana) and spongy iron sponges (tomahagane) are banned from leaving Japan. Despite numerous analogies the Japanese method of producing swords from spongy iron differs significantly from the method used in ancient and medieval Europe. We do not know the details concerning forging techniques used by ancient sword-makers, however we know their most important qualities. Such swords known as damascenced swords are not forged from one type of steel but have a structure similar to puff-paste. Such "paste" called forged damascene iron is made of hundreds or even thousands of alternating iron layers: hard (elastic) and soft (resistant to stikes and breaking).