In February 1921, he opened Shimano Iron Works in Higashi Minato in Sakai City when he was 26 years old. On the site of a demolished celluloid factory, he rented a nearly 40-square-meter area. The monthly rent was 5 yen. At that time, the new establishment had only a single lathe, measuring about 1.8 meters long. He had borrowed that machine from Sano Iron Works, benefiting from his friendship with its owner.