Thanks for visiting my vintage Hamilton watch blog. I like to restore US-made Hamilton wrist watches back to their original glory and share my experiences with other enthusiasts. Use the "Search" space below if you know what model you're looking for. Feel free to leave polite comments or questions in the spaces provided. Also check out my "watches for sale" on my Etsy site - the link is on the right, just below.

Saturday, February 9, 2013

1955 Automatic K-150

For decades Hamilton used men's names as model names.  Despite this prevalent trend and even though there are lots of names that were never used, Hamilton adopted a numbering approach to many watches in the 1950's.  A good example is the 1955 Automatic K-150.  This watch was made for three years.

Hamilton's approach to numbering involved using the first number to denote the case material.  A 1 was used to indicate 18K solid gold as the case material.  A 2 represents a solid 14K gold case.  A 3 is solid 10K gold, 4 is gold filled and 5 is stainless steel.

Another interesting factoid is if the second digit has a 5, then the watch will have a stainless steel back.

Understanding that, you would probably guess the K-150 has an 18K solid gold case with a stainless steel back - which it does.

I recently had an opportunity to overhaul a K-150 for a friend.  It was a treat for me since I don't tend to see solid gold watches unless they are in a shop.

The K-150 has an textured dial with an embossed Hamilton logo and solid 18K numerals and markers.  The pearlized minute track is inside the numerals circumference so the watch features a shorter second hand to align with the smaller diameter.

Behind the dial, you'll find a Hamilton 661movement.

Identifying models can sometimes be a challenge but a good percentage of the time the model name is stamped inside the case back.


  1. Hello Dan. I just love your Web page and all the information you provide to the community. I have recently and luckily found at a yard sale a 1955-57 Hamilton K-150 like the one you overhauled in the pics above. Mine ticks when moved and sounds strong but is missing all the hands and the crystal and I cannot find the part numbers for these missing parts so I can try and assemble it into a complete watch. I tried using the parts catalog but to no avail. Would you know off hand what the part numbers are and where to look to buy them? Thank you in advance. Michael

    1. Hey Michael - look for a loose 661 on eBay with the right style hands. If you want new hands the hole sizes for the hour, minute and second hands are 1.50 x 0.90 x 0.18mm, respectively. You just need to measure or estimate the correct length by measuring the distance from the center of the dial to the pearled track (for the hour) and to the hour figures for the minute. You'd probably have to trim the second hand.

      The crystal is much easier - measure the bezel opening (to the tenth of mm) and get a GS PHD style crystal in a size that is slightly larger.