Thinline 4004
1963–1964 · 10k YGF · Manual Wind
About the Thinline 4004
Made from 1963 through 1964, the Thinline 4004 runs on Hamilton's caliber 687, a 17-jewel manual wind movement housed in a 10K yellow Gold Filled case. The Thinline family was Hamilton's answer to the growing demand for slim dress watches in the early 1960s, and the 4004 represents one of the thinner, cleaner expressions of that idea. The dial is silver with textured gold numerals and markers, a subseconds register at 6 o'clock, and numerals only at 12 and 6.
The vertical texture on the dial is what makes the 4004 visually interesting up close, a detail that photographs poorly but reads well in person. Finding one with that texture intact and unmarked takes some patience, since silver dials from this era are prone to spotting and hairlines from improper cleaning over the decades. The Gold Filled case holds up reasonably well when it has been worn regularly rather than left to sit, but check the high-contact points around the lugs and crown for wear-through.
From the Catalog
Hamilton described the Thinline series as offering an incredibly compact construction with a super-slim streamlined profile, and positioned it as a dress watch with real weather protection built in. The 4004 retailed for $75.00 on a strap or $85.00 on a bracelet in 1963.
Hamilton Catalog Images
1963
1964
What to Look For
| Dial | Look closely at the vertical texture. It should be even and unmarked. Spotting, cloudiness, or uneven fading often points to moisture intrusion or a past cleaning attempt gone wrong. Check the numeral and marker surfaces for chips or separation from the dial. |
| Crystal | These left the factory with acrylic crystals. Check for deep scratches or a hazy center, which usually means the crystal has been polished repeatedly. A clean replacement crystal is inexpensive and often the right call. |
| Movement | The click spring in the caliber 687 is prone to dislodging during cleaning, so ask whether the watch has been recently serviced and by whom. Oil in a movement this age dries out completely over decades, creating enough friction to stop the watch or degrade its rate significantly. |
| Case | This is a 10K yellow gold-filled case, so check the lug edges and the area around the crown for wear-through to the base metal. The hidden lug style means wear there can be easy to miss at first glance. |
| Crown | Check that the crown winds smoothly and sets the hands without slipping. A crown that feels gritty or loose in the stem is worth flagging before purchase. |
The Movement
The caliber 687 is a 17-jewel manual wind movement made by Hamilton in the United States. It is a compact, reliable caliber built for slim dress watch cases, and it winds and sets with a clean, precise feel when it has been properly serviced. Like all movements of this age, it benefits from a full service if it has not had one recently.