Automatic K-350
1954 · 10k Solid Yellow Gold / Stainless Steel · Automatic
About the Automatic K-350
Made only in 1954, the Automatic K-350 belongs to Hamilton's early Automatic family and runs on the caliber 661, a 17-jewel automatic movement. The case is 10K yellow gold with a stainless steel back, and the dial came in two versions: a plain silver butler-finished dial and a black-finished dial, both with solid 18K gold luminous markers. Sweep seconds was standard, and Hamilton listed it as water resistant, shock resistant, and anti-magnetic for its time.
The 18K solid gold markers are worth examining closely on any example you come across. On unserviced watches that have been exposed to moisture over the decades, luminous material on those markers can deteriorate unevenly, and the black dial variant in particular shows any aging or spotting quite visibly. Both dial versions have real presence for a round-cased watch from this era, and the swept lugs give the case a more elegant profile than many of its contemporaries.
From the Catalog
Hamilton's 1954 catalog described the K-350 as having a natural gold case with stainless steel back, solid 18K gold luminous markers on either a plain or black dial, and sweep seconds, with water resistance, shock resistance, and anti-magnetism listed as standard features. Both dial versions carried the same original retail price of $115.00.
Hamilton Catalog Images
1954
What to Look For
| Dial | Check the 18K gold markers carefully. The luminous material can deteriorate or pit with age, and any moisture exposure tends to show up as uneven discoloration around the markers. On the black dial version, look across the surface at an angle for any burning or scorching near the center, which can occur from close contact with the hands over decades of use. |
| Crystal | This case opens through the crystal, not through the case back. Look for scratch marks or chips around the crystal edge and bezel, which often appear on watches where someone tried to pry open the case back instead. A damaged bezel or gouged crystal edge is a common sign of improper servicing attempts. |
| Movement | The caliber 661 is an automatic, and dried oil creates enough friction to stop it entirely on examples that have sat unserviced for years. Ask about service history. A watch that winds freely by hand but won't run reliably through normal wear is a classic sign of a movement that needs attention. |
| Case | The case is 10K yellow gold with a stainless steel back. Check the lugs for wear-through, especially on the high points where a strap or bracelet makes contact over years. The gold fill layer on 10K cases can thin noticeably with heavy use. |
| Crown | Check that the crown screws or presses in properly and that the stem doesn't feel loose or wobbly. Even though this watch was listed as water resistant when new, no vintage watch should be trusted near water today, and a compromised crown seal is the most common point of moisture ingress. |
The Movement
The caliber 661 is a 17-jewel Swiss-made automatic that Hamilton used through the 1950s. It winds itself through a rotating oscillating weight that captures energy from the wearer's movement, so it doesn't need daily manual winding under normal wear. The movement has a solid service record when properly maintained, but like any automatic of this age, dried lubricants are the most common cause of poor timekeeping or stoppage.