Thinline 6500
1968–1970 · 10k Rolled Gold Plate / Stainless Steel · Manual Wind
About the Thinline 6500
Made from 1968 through 1970, the Thinline 6500 is part of Hamilton's Thinline family, a line built around slim profiles and clean modern design. It runs on the caliber 639, a 17-jewel manual wind movement, and came in both 10K yellow RGP/SS and 10K white RGP/SS case options. The cushion case shape gives it a slightly softer geometry than the more strictly rectangular Thinline models, which makes it an interesting variation within the family.
The gold dial with applied gold markers and Arabic numerals at 3, 9, and 12 gives the 6500 a restrained, dressy look that holds up well when the dial is clean. Condition on these dials varies considerably, so spotting one with no spotting, separation of the applied elements, or discoloration around the edges is worth paying attention to. The two-tone case options also mean there is a bit of choice for buyers who have a preference between yellow and white.
From the Catalog
Hamilton listed the Thinline 6500 at $89.50 in 1968, positioning it as a dressed-up option with a mesh bracelet, a clean dial with applied stick and Arabic numeral markers, and the Hamilton logo placed just below 12.
Hamilton Catalog Images
1968
1971
What to Look For
| Dial | Look closely at the gold dial for spotting, discoloration, or any separation around the applied gold markers at 3, 9, and 12. Even minor moisture intrusion can leave marks that are difficult to reverse, so a clean, evenly finished dial is a meaningful sign of how the watch has been stored. |
| Crystal | Check the crystal for chips, deep scratches, or crazing. A compromised crystal is often the first sign that the case seal has been breached, which matters for dial condition as well. |
| Movement | The caliber 639 has very little clearance between its overlapping parts, which makes dried oil a genuine concern. A watch that has been sitting unworn for years may feel like it winds and sets fine, but still not run reliably until serviced. Confirm it is running and tracking time reasonably before assuming it is ready to wear. |
| Case | The 10K RGP/SS construction means the gold layer is relatively thin. Check the high points of the cushion case, especially the lugs and any edges, for wear through to the base metal. Some wear is expected on a watch this age, but heavy loss of the gold layer affects both appearance and value. |
| Crown | Work the crown through winding and setting positions and confirm it moves smoothly without slipping or grinding. The case back on these can be tricky to open, so if there is any question about whether the movement has been serviced, factor that into your assessment. |
The Movement
The caliber 639 is a 17-jewel manual wind movement built to fit a slim case profile. It winds by the crown, keeps a subseconds hand running off a dedicated wheel, and is reasonably robust when properly oiled, but that last part is the catch. With very little clearance between its working parts, this movement is more sensitive to dried lubricants than some others, and a watch that has been sitting for years will often need a full service before it runs as it should.