40 centimeters. According to the data of pancake fruit seeds, the thickness of Tianjin pancake fruit seeds is 40 cm, and 40 cm is enough. 45 cm is more difficult and difficult to operate, and sometimes a cake is not easy to spread. Pancake roe is a famous snack in Tianjin. Tianjin people take it as breakfast. It consists of mung bean flour pancakes, eggs, fried dough sticks or crispy "grate", with flour paste, chopped green onion, fermented bean curd and Chili sauce as seasoning.