Thinline 6508
1968–1970 · 10k RGP / Stainless · Manual Wind
About the Thinline 6508
Made from 1968 through 1970, the Thinline 6508 is part of Hamilton's Thinline family, which pushed toward slimmer profiles and cleaner aesthetics through the late 1960s. It runs the caliber 637, a 17-jewel manual wind movement, housed in a square 10K yellow RGP case with a stainless steel back. The white dial carries applied gold markers with no printed numerals, and a subseconds register at the bottom of the dial adds a bit of visual structure to an otherwise restrained layout.
Surviving examples vary more than you might expect for a single-year model. The known dial variant with seconds cross-hairs and black baton hands is the detail worth confirming before buying, since the cross-hair printing around the subseconds register is fragile and prone to fading or flaking. Applied gold markers hold up better than printed numerals over time, but check closely for any that have separated from the dial or shifted position.
From the Catalog
Hamilton listed the Thinline 6508 at $59.50 in 1968, describing it simply as a 10K yellow top model. A bracelet-equipped version was also offered that year at $69.50, suggesting the base price covered the watch on a strap.
Hamilton Catalog Images
1968
What to Look For
| Dial | Look closely at the subseconds register area. The cross-hair printing around it is delicate and often shows fading, flaking, or partial loss on examples that have not been stored carefully. The applied gold markers should sit flush and even, any that have separated from the dial or tilted are difficult to reset without a dial restoration. |
| Crystal | The square case takes a flat crystal, and replacements are available, but confirm the fit is correct with no gaps at the edges. A loose or ill-fitting crystal on a watch this slim can allow dust in quickly. |
| Movement | Oil in a caliber 637 of this age has almost certainly dried out. Dried lubricant creates enough friction to degrade timekeeping noticeably, and in worse cases will stop the watch under normal wear. A service is not optional on one of these, it is the starting point. |
| Case | The 10K yellow RGP surface on the case top can show wear through to the base metal on the high points of the lugs and case sides. The hidden lug style makes polishing history harder to spot, so examine the case edges under good light for any rounding that suggests aggressive cleaning. |
| Crown | Stem removal on the caliber 637 carries a real risk of breaking the set lever tip if it is not done carefully. Ask whether the crown and stem have been disturbed, and check that setting and winding feel smooth with no slop or grinding. |
The Movement
The caliber 637 is a 17-jewel manual wind movement made for Hamilton's thinner dress watch line. It is a straightforward and reliable design, though its compact construction means that servicing requires patience and a steady hand, particularly around the setting mechanism. Wind it daily and it keeps good time, but it does need fresh oil to do so.