You can get the "birthdate" of your sewing machine by calling Singer at 1(800)4SINGER. This isn't the actual date your machine was made, but the date that a group of serial numbers was allotted to a particular model number. Some of the allotments were for as many as 50,000 machines.

The following information is very incomplete.
Most of it has been taken from information reported by individual Featherweight Fanatics.

There is much room for error. Many serial numbers are very hard to read. And Singer's records are NOT computerized! The paperwork Singer is using to report the "birthdates" can also be difficult to dicipher. To see an example of a page from Singer's records, click here.

Numbers only Numbers only - No prefix
Single letter followed by numbers A = Poldolsk, Russia (began 1911, no other info available)
B = Elizabeth, New Jersey, USA
C = Wittenberge, Germany (began 1908, no other info available)
D = Elizabeth, New Jersey, USA
E = Poldolsk, Russia (began 1908, no other info available)
F = Clydebank, Scotland, UK
G = Elizabeth, New Jersey, USA
H = Elizabeth, New Jersey, USA
J = Clydebank, Scotland, UK
K = Elizabeth, New Jersey, USA
L = Elizabeth, New Jersey, USA
M = Clydebank, Scotland, UK
N = Elizabeth, New Jersey, USA
P = Clydebank, Scotland, UK
R = Clydebank, Scotland, UK
S = Clydebank, Scotland, UK
S = Poldolsk, Russia (100 "S" machines made in Poldolsk, no other info available)
T = Poldolsk, Russia (began 1906, no other info available)
V = Clydebank, Scotland, UK
W = Bridgeport, Connecticut, USA (began 1906 or 1911, no other info available)
X = Clydebank, Scotland, UK (began 1919, no other info available)
Y = Clydebank, Scotland, UK
Two letters followed by six numbers  AA to AT = Elizabeth, New Jersey, USA
BA to BY = Elizabeth, New Jersey, USA (began 1924, no other info available)
CA to CY = Bogota, Columbia (began 1964, no other info available)
DA to DY = Karachi, Pakistan (began 1962, no other info available)
EA to EY = Clydebank, Scotland, UK
FA to FY = Clydebank, Scotland, UK
GA to GY = Clydebank, Scotland (began 1935, no other info available)
HA to HY = Istanbul, Turkey (began 1960, no other info available)
JA to JE = St. Johns, Quebec, Canada
KA to KY = Buenos Aires, Argentina (began 1959, no other info available)
LA to LY = Taytay, Philippines (began 1959, no other info available)
MA to MY = Monza, Italy
NA to ND = Anderson, South Carolina, USA
ND to NY = Taichung, Taiwan (no info available)
PA to PY = Karlesruhe, Germany
RA to RY = Campinas, Brazil (began 1954, no other info available)
SA to SN = Bonnaires, France (began 1935, no other info available)
SP to SY = Lima, Peru (began 1963, no other info available)
TA to TY = Utsunomiya, Japan (began 1956, no other info available)
VA to VY = Penrith, NSW, Australia (began 1957, no other info available)
WA to WY = Santiago, Chile (began 1967, no other info available)
YA to YY = Queretare, Mexico (began 1959, no other info available)
If your machine is not on one of these databases, contact Singer for information. Call them at 1-800-4SINGER, or if you are outside the U.S., email them at TalkToUs@SingerCo.com. They will be able to give you your machine's "birthdate" as well as date your machine. You can also get general birthdate info at: http://www.singerco.com/support/serial_numbers.html.