The world's hardest tree - The iron birch
The iron birch tree is usually about 20 meters tall, with a trunk diameter of about 70 cm and a life span of about 300-350 years. The bark is dark red or nearly black, densely covered with white spots. The leaves of the tree are oval. It has a small production area, mainly in southern Korea and the border area between Korea and China, with some along the southern seashore of the USSR. It was once used as a substitute for metal products when steel was in short supply, and because of its high density, it does not rot in long blisters, and even after cutting open the inside of the tree, the heart of the tree is still dry, so in the former Soviet Union even used iron birch to make bearings for speedboats.
Iron birch can be said to be more than double the hardness of steel, about HRC100, it is at least three times harder than ordinary oak, so it is said that in ancient times when cutting iron birch, the ancients were using hammering metal, that is, burning or scalding with fire, so every time when cutting iron birch, the ancients will carry iron brand, iron birch bark scalding for a while, here the hardness will be significantly reduced some, or else directly cut, it is easy to cut the axe.
Iron birch can be said to not only have the hardness of steel, but also perfectly avoid the shortcomings of steel, such as resistance to blisters which is very good to use, in ancient times metal products things, especially steel and copper products are very easy to rust, because there was no coating technology, so iron birch has become a good substitute, and the former Soviet Union at the time due to the lack of steel production, but also once used iron birch, so iron birch can be used in many places, such as aviation, military and everyday utensils.
And iron birch is also the most fear of insects a tree, because it is extremely dense, basically insects have no way to mouth, so the ancient chariot, waterwheel and other key parts are used iron birch as raw materials, and even some people even build houses using iron birch, and such houses tend to stay longer, and even in a rainy environment, these houses are still not troubled by water blisters and insects.
Of course it is because the iron birch tree has so many advantages that people cut and use it in large quantities, especially in the Ming Dynasty when the fire method was invented to cut the iron birch tree, the processing of the iron birch tree showed a trend of scale, and after that its number gradually decreased, resulting in the iron birch tree has now become a national protected species, basically endangered species, is prohibited to cut.
