For additional information, noodles with the diameter no less than 1.3 mm and no more than 1.7 mm is defined as cold noodles, and those with a diameter no less than 1.7 mm are classified as udon.
ちなみに直径1.3mm以上1.7mm未満はひやむぎ、1.7mm以上はうどんと分類される。