1959 Thin-o-Matic T-401

There are at least 57 different Thin-o-matic models, even more if you consider the diamond dial options, and even quite a few more when you consider the Dateline T-series.   They don't all use micro-rotor movements but the majority of them do.  The pink micro-rotor movements were made by Buren and the silver Dateline T-series also used Buren movements.  Buren also made a few of the Thinline manual wind movements.  In the 1960's Hamilton partnered with Buren and eventually acquired them.  In 1969 when Hamilton's US production was shut down, production moved to Buren's factory in Switzerland.

Out of all of the different Thin-o-matics produced, only one as cased in a square case.  It was the 1959 Thin-o-matic T-401 and was produced for four years.   

The T-401 was the second of only two square automatics.  The other came out earlier as the Automatic K-405 which I recently posted.

The T-401 was cased in 10K gold filled and featured solid 14K numerals and markers on a sterling silver dial.  You could get it with a bracelet or on a strap.  The dial also has a pearled track of gold dots to represent the seconds track (or minutes, I suppose).

The movement is a 17 jewel 663 movement, which looks a lot like all the other pink micro rotors, like the 666, et al.

All the parts are disassembled and ultrasonically cleaned.  There are a LOT more parts to a micro rotor and most of the arbors of the various wheels are long and difficult to get aligned when reinstalling the bridges. 

Piece by piece the movement is reassembled and ticking away with a good motion.  Now it's time to see what the watch timer things.

Not too shabby... good amplitude and the beat error is within my specs of less than 3.0.  The beat error is very challenging to adjust with this movement so I'm glad to not have to attempt it.

Everything goes back into the case and it's much shinier now.  The watch has 3/4" lugs so I'll need to find a 19mm strap.