Accumatic A-511
1971 · Stainless Steel
About the Accumatic A-511
The Accumatic A-511 was made only in 1971, a round stainless steel automatic from Hamilton's long-running Accumatic line. It runs on the caliber 689, a reliable self-winding movement that powered a number of Accumatics during this period. The Accumatic family represented Hamilton's accessible automatic offering, and the A-511 fits into that lineup as a clean, unfussy dress watch from the brand's later American-era production.
Finding one in honest, unpolished condition is worth more than a case that's been buffed smooth, the original crisp edges on these swept lugs are part of what makes them appealing. The applied indices are a detail worth examining closely in person, since replacements or repairs often show under magnification. Dials from this era can also be fragile, so any signs of lifting or moisture damage are worth factoring into your assessment.
Hamilton Catalog Images
1971
What to Look For
| Dial | Look closely at the applied indices for any that are loose, tilted, or replaced. The dial surface itself is vulnerable to lacquer damage if it's ever been cleaned improperly, check for streaking, fading, or uneven texture under a loupe. |
| Crystal | Check for deep scratches or crazing. A replacement crystal is an easy fix, but confirm it's properly seated and not sitting proud of the bezel. |
| Movement | Dried oil creates enough friction to stop the caliber 689 even when it appears to wind normally. If the watch runs but loses time significantly, a service is almost certainly overdue. Ask when it was last serviced. |
| Case | Stainless steel holds up well but check the lug tips for thinning from past polishing. Original case finish should show some brushing or texture, heavily polished examples have lost definition. Case backs can be stubborn to open, so pry marks around the back edge are a common find. |
| Crown | Work the crown through all positions to confirm smooth winding and positive engagement. On watches of this age, a worn or replaced crown is common and not a dealbreaker, but confirm the stem sets the hands cleanly without slipping. |
The Movement
The caliber 689 is a 17-jewel automatic movement made by Hamilton. It winds via a bidirectional rotor and keeps reasonably accurate time when properly serviced. Like most automatics from this era, it benefits from a full service every few years to keep the oils fresh and the parts moving freely.