Fuji Seimitsu Co., Ltd. is a comprehensive manufacturer of self-locking nuts with industry-first metal ring locking capability. Fine U-NUTs are self-locking nuts developed for fastening bearings used in particularly harsh environments. Key groove processing on the shaft is not required, increasing "rationality" and "safety" of work processes. Even easier mounting gives excellent "workability". Increased performance of various machinery products, higher product quality and lighter weight has led to "safe" and "reliable" products with a great reputation.