Automatic K-407
1956–1957 · 10k Yellow Gold Filled · Automatic
About the Automatic K-407
Made from 1956 through 1957, the Automatic K-407 is part of Hamilton's broader Automatic family from the mid-1950s, a period when Hamilton was pushing hard on self-winding design for everyday wear. It runs on the caliber 661, a 17-jewel automatic movement, and comes in a round 10K yellow Gold Filled case with a choice of white or black dial. The applied gold numerals and markers, luminous dots, and pearled chapter ring track give the dial a dressy, layered look that was very much in step with mid-century American watch design.
Both dial variants show up with some regularity, though finding one with a clean, unburned dial takes patience. The black dial in particular is worth inspecting carefully for any fading or spotting, as dark dials from this era can be unforgiving when conditions haven't been kind to them.
From the Catalog
Hamilton listed the K-407 in 1956 with a 10K yellow gold-filled case, applied gold numerals and markers, luminous dots, and a pearled chapter ring track on either a white or black dial, and advertised it as waterproof. Pricing started at $95 on a strap and reached $100 on a bracelet, reflecting the watch's position as a serious everyday automatic with some genuine dress sensibility.
Hamilton Catalog Images
1956
1957
What to Look For
| Dial | Look closely at the dial surface around the hands for any burn marks or discoloration. Dials from this era could suffer heat damage from hands sitting too close over time. The applied gold numerals should be crisp and evenly seated, with no separation at the edges. On black dial examples, check for fading or silvering near the center. |
| Crystal | The K-407 uses a domed acrylic crystal. Expect some light surface scratching on unpolished examples, which is normal and can be buffed out. Deep gouges or crazing are harder to address and can detract from the finished look. |
| Movement | Oil dries and thickens on any automatic that has sat unused for years, and enough friction can build up to stop the rotor and mainspring from doing their jobs. Ask about service history. A caliber 661 that winds but won't run reliably is almost always an oil issue rather than a parts problem. |
| Case | The 10K gold-filled case should be inspected at the lugs and bezel edges for wear-through to the base metal. Some spotting or brass showing through is worth negotiating on price, but heavy wear cannot be reversed. |
| Crown | The K-407 was rated waterproof in its day, but no vintage watch should be treated as water-resistant now. Check that the crown threads in smoothly and seats flush. A crown that wobbles or feels loose may indicate a worn or replaced stem. |
The Movement
The caliber 661 is a 17-jewel automatic, meaning it winds itself through the motion of the wearer's wrist via a rotating oscillating weight. It is a reliable workhorse from Hamilton's American production era, compact enough for a round dress case and well-suited to daily wear. Like most automatics of its age, it rewards a fresh service and runs noticeably better with clean oil throughout.