Automatic K-412
1958–1959 · 10k Yellow Gold Filled · Automatic
About the Automatic K-412
Made from 1958 through 1959, the Automatic K-412 runs on Hamilton's caliber 661 and comes in a 10K yellow Gold Filled circular case. It belongs to Hamilton's Automatic family, a broad grouping of domestic self-winding watches that preceded the more tightly branded Accumatic line. The dial is white with embossed gold numerals and markers at the even-hour positions, luminous dots, and a pearled minute track with tiny golden dots, a detail that gives it a quiet richness you don't always see on round automatics from this period.
Embossed dials are more vulnerable to damage than printed ones, so the condition of the numerals and markers is the first thing worth examining closely. The luminous material on older examples may have discolored or flaked, which is common and expected, but the embossed elements should sit cleanly with no separation or corrosion. Finding one with the dial intact and the pearled track still crisp is genuinely satisfying.
From the Catalog
Hamilton marketed the K-412 in 1958 as a waterproof automatic with a 10K yellow gold-filled case and the distinctive pearled minute track dial, pricing it at $100 on bracelet, a solid price point for a domestic automatic at the time.
Hamilton Catalog Images
1958
1959
What to Look For
| Dial | Look closely at the embossed numerals and markers, they can chip, pull away from the dial, or show corrosion over time, especially if moisture ever got inside the case. The luminous dots may have yellowed or darkened, which is normal, but check that none are missing or flaking. The pearled minute track is a small detail that distinguishes this dial, so look for any wear or loss along that track. |
| Crystal | Check for crazing, deep scratches, or chips around the edges. A replacement crystal is straightforward, but confirming it sits flush and seals correctly matters, this case relies on the crystal to maintain its enclosure. |
| Movement | Ask whether the caliber 661 has been serviced. Dried oil creates enough friction to stop an automatic movement entirely, and a watch that winds but doesn't run consistently likely needs a full service. A smooth-winding rotor and steady sweep seconds hand are good signs. |
| Case | The 10K gold-filled case can show wear through to the base metal at the lugs and high points, check those areas carefully. Also look at the case back for pry marks or tool marks, which can indicate improper opening attempts in the past. |
| Crown | Pull the crown gently and confirm it moves between positions without slipping or feeling loose. A worn crown or damaged stem affects setting and, on an automatic, the manual winding function as well. |
The Movement
The caliber 661 is a 17-jewel automatic movement made by Hamilton in the United States. It winds itself through a rotating weight that moves with the motion of the wrist, and it beats at a rate that drives a smooth sweep seconds hand rather than a ticking one. It's a reliable movement when properly serviced, though like any automatic from this era, it benefits from fresh oil and a timing check if it hasn't been looked at in a while.