A U.S. B-1 Business Visa can be valid for up to 10 years, depending on your nationality and the visa agreement with the United States. However, the length of each stay in the U.S. is typically limited to a maximum of 6 months per visit, as determined by U.S. Customs and Border Protection at the port of entry.
It is important to note that having a 10-year visa does not mean you can stay for 10 years continuously, it only allows multiple entries during the validity period, with temporary visits for business each time.