It is therefore my goal to establish a database of serial numbers for the above models and create an accurate Year of Issue, which is the year of manufacture or year your sewing machine was actually made.
Singer - Machine Serial Numbers Up to March 1996 you could call Singer Customer Service with your serial number and they would give you a of for models 301, 301A, 401A and 403A.
What this tells us is 1 million "NA" serial numbered sewing machines were manufactured in 1951, 1 million "NB" serial numbered sewing machine were manufactured in 1956 and 1 million "NB" serial numbered sewing machine were manufactured in 1961.
Anderson, South Carolina Singer had one United States manufacturing factory, Elizabethport, located in Elizabeth, New Jersey.
I also used specific events, assorted reference materials, original owner purchase receipts and instruction manual revised dates.