Mortise and Tenon Secret

In the interstellar wasteland, humans can only weld. After three hundred years of welding, the most advanced mecha is just a pile of iron sheets put together. Welds were the only way to connect them—they cracked when touched and fell apart when knocked. Su Yan dug out a book without a cover from under the rubble. Welds are not shown in the book. What is painted is the mortise and tenon joint. The dovetail tenon is narrow at the bottom and wide at the top, and the Luban dark pattern with convex and concave interlocking patterns. No need for a welding rod or a drop of molten iron. Two pieces of iron bite together - they cannot be broken apart or taken apart. He made three mechas. Bai Qi. Li Jing. Yu Chigong. No welding. Bite. The mecha that has been welded for three hundred years will break if touched. He chewed something for a day and couldn't open it. Someone asked him: What is your craft? Su Yan said: Luban's. Later, the Allied Forces of the Universe searched through the ruins of the ancient battlefield, trying to find the source of this technology. They found a mecha - the frame was not welded, but chewed. It has not been loosened for three thousand years. They can't take it apart. Su Yan didn't care either. He's doing Channel 4. Channel 5. Channel 6. When Channel 7 was finished—— The three paths of Buddhism, Taoism, and witchcraft come to an end, and the three paths merge into one. Pangu. At that time, the whole universe understood one thing: people who are welded together will fall apart with a knock, but people who are bitten together will not.