Thinline 4008
1968–1970 · 10k Yellow Gold Filled · Manual Wind
About the Thinline 4008
The Thinline 4008 was produced from 1968 through 1970, part of Hamilton's Thinline family, which represented the company's push toward slimmer, more dressy automatic and manual-wind designs during the late 1960s. It runs on the caliber 639, a 17-jewel manual-wind movement, housed in a 10k yellow Gold Filled round case. The dial is silver with applied stick markers and an H logo below 12, with gold hands and a subseconds hand. Hamilton offered it on a finely woven mesh bracelet or a strap, with the bracelet version retailing at $85 in 1968.
Applied stick markers on a silver dial can show wear at the feet where moisture gets underneath, so look closely for separation or discoloration at each marker's base. The mesh bracelet, when original, adds real appeal to this model, but finding one with its bracelet intact and in good condition takes some patience. The overall dressy character of this watch makes condition especially important, since the slim case and clean dial leave little to hide any accumulated wear.
From the Catalog
Hamilton's 1968 catalog positioned the Thinline 4008 as a dressy, slim option for someone who wanted a round gold-filled watch with a refined look, offering it at $85 on bracelet or $75 on strap, with the finely woven mesh bracelet being a notable part of its appeal.
Hamilton Catalog Images
1968
What to Look For
| Dial | Check each applied stick marker carefully. Moisture trapped underneath can cause the feet to pull away from the dial or leave dark halos on the silver dial. Look across the dial surface at an angle to catch any raised or shifted markers. |
| Crystal | The round case takes a standard mineral or acrylic crystal. Acrylic crystals on watches this age often show fine scratches that a watchmaker can polish out, but check for deep gouges or chips at the edge that would require replacement. |
| Movement | The caliber 639 has very little clearance between its overlapping parts, which makes a full service genuinely delicate work. Ask whether the watch has been serviced recently, and by whom. Dried oil in a movement this age creates enough friction to stop it even when the mainspring still has tension. |
| Case | 10k yellow gold-filled cases from this era can show brass bleeding through at the lugs and case edges where plating wears first. Check those areas under good light before buying. |
| Crown | Wind the crown slowly and feel for grinding or slipping. The set lever tip in the 639 can break during stem removal if the movement has not been serviced carefully, so a crown that pulls out unevenly or feels loose deserves a closer look at the movement. |
The Movement
The caliber 639 is a 17-jewel manual-wind movement made for Hamilton's slimmer dress watch cases during this period. It winds from the crown and drives a subseconds hand at 6 o'clock. It is a well-made movement, but the tight tolerances between components mean that servicing it requires patience and experience, and old dried oil can bring it to a stop even when the mainspring is fully wound.