Thinline 2031
1968–1969 · 14k Solid Yellow Gold · Manual Wind
About the Thinline 2031
Made from 1968 through 1969, the Thinline 2031 is a 14K yellow gold dress watch from Hamilton's Thinline family, which positioned the brand squarely in the market for slim, refined watches during the late 1960s. The Thinline family as a whole is covered in its own dedicated guide, but this model occupies the cleaner, more minimal end of the lineup. Power comes from the manual-wind caliber 688, a 17-jewel movement well-suited to the slim case profile. The silver dial carries applied gold numerals and applied gold markers, with a date window at 3 o'clock.
Solid gold cases from this era are prone to wear at the lugs and caseback edges, so examine those areas closely before buying. The dial on this model is worth close inspection too, as silver dials from the late 1960s can show fine hairline cracks or spotting near the edges that photographs don't always reveal. Finding one with original, undamaged applied markers and a crisp date window is the real goal.
From the Catalog
Hamilton listed the Thinline 2031 in its 1968 catalog simply as a 14K yellow gold Thinline at $150, keeping the description brief in keeping with the clean, uncluttered character of the watch itself.
Hamilton Catalog Images
1968
What to Look For
| Dial | Look carefully at the applied gold numerals and markers. Over decades, the adhesive or feet holding applied indices can fail, and a shifted or missing marker is a meaningful restoration cost. Check the date window at 3 o'clock for proper alignment and a clean, undamaged cyclops or flat lens over the aperture. |
| Crystal | These watches left the factory with a mineral or acrylic crystal depending on configuration. Inspect for deep scratches, chips at the edge, or a replacement crystal that sits poorly in the bezel. A well-fitted original or period-correct replacement matters on a gold dress watch like this. |
| Movement | Ask about service history for the caliber 688. Dried oil in a movement this age creates friction that can stop the watch or accelerate wear on pivot points. A running watch is not the same as a properly serviced one. |
| Case | 14K yellow gold wears differently than gold-filled or gold-plated, but it still shows wear at the lug tips and caseback rim. Look for deep gouges from improper caseback opening, which is unfortunately common on solid gold cases. The caseback itself can be tricky to open, and tool slips leave marks that are hard to ignore on a gold case. |
| Crown | Pull the crown gently through its positions and check that winding feels smooth and date setting engages cleanly. The crown can separate from the stem if someone has pulled it too forcefully, so confirm it seats fully and winds without slipping. |
The Movement
The caliber 688 is a 17-jewel manual-wind movement made for Hamilton by ETA during the period when Hamilton was transitioning much of its production to Switzerland. It is a reliable, compact movement that fits well inside slim dress case profiles without the bulk of Hamilton's earlier American-made calibers. Servicing it requires attention during reassembly, as aligning the wheel train with the bridge is exacting work and forcing any component risks breaking a pivot.