Square Cut Corner Plain
1927–1930 · Gold Filled
About the Square Cut Corner Plain
The Square Cut Corner Plain comes from Hamilton's so-called geometric era, when the company was naming wristwatch models after their case shapes rather than romantic or aspirational names. Made from 1927 through 1930, this small rectangular watch measures 28.5mm wide and 8.4mm thick, with the distinctive cut corners that give the case its name. It runs the caliber 987, a 17-jewel movement that Hamilton used across many of its dress watches of that period. Cases were offered in 14K Gold Filled or solid 14K gold, in yellow, green, or white.
Finding one today means navigating nearly a century of use, and the cut corners on the case are exactly where wear tends to concentrate, so pay attention to the bezel edges near the crystal. The dial spec calls for white with black Arabic numerals, and originals in clean, unrestored condition are genuinely hard to come by. The three metal color options mean there is some variety to hunt across, and solid gold examples carry a different weight and presence than the Gold Filled versions.
From the Catalog
Hamilton's 1929 catalog offered the Square Cut Corner Plain in 14K filled gold at a consumer price of $57.00, with solid 14K gold versions priced at $87.00, available in yellow, green, or white in both cases. The dial spec was straightforward: white with black Arabic numerals, referenced internally as dial number 018.
Hamilton Catalog Images
1929
1930
What to Look For
| Dial | White dial with black Arabic numerals is the original configuration. Look for cracks, chips, or amateur touch-ups, especially around the numerals. Refinished dials are common on watches this age and will affect value. |
| Crystal | The cut corners on this case require a correctly shaped crystal. Confirm the crystal fits properly at the corners without gaps or overhang, as ill-fitting replacements are a common shortcut. |
| Movement | Dried oil in a movement this age creates enough friction to stop it even when the mainspring still has tension. A watch that runs briefly then stops is a classic sign. Budget for a full service regardless of whether it is running. |
| Case | The bezel near the cut corners is extremely prone to wear. Inspect those areas closely for thinning, denting, or polishing that has softened the original lines. On gold filled examples, check whether any base metal is showing through. |
| Crown | Check that the crown is original to the period and threads or seats properly. A mismatched or loose crown is easy to overlook but worth addressing before the watch goes into regular wear. |
The Movement
The caliber 987 is a 17-jewel manual wind movement that Hamilton relied on heavily through its geometric-era dress watches. It is a small, relatively thin movement built for slim rectangular cases, and it performs well when properly serviced. The balance is a known fragile point on this caliber, with both the pivot and hairspring requiring careful hands during any adjustment work.