Datomatic A
1954–1955 · Stainless Steel · Automatic
About the Datomatic A
The Datomatic A was produced from 1954 through 1955, placing it among Hamilton's earliest automatic date watches. It runs on the ETA caliber 1258, a 17-jewel Swiss automatic that Hamilton sourced as it expanded its use of Swiss movements in the mid-1950s. The stainless steel case is round, fitted with a silver dial carrying embossed gold numerals and markers, and a sweep seconds hand that gives it a clean, modern read for its era. The Datomatic name signals the date complication, which was still a genuine selling point at this point in watchmaking history.
Finding a Datomatic A in good shape means paying close attention to the dial, where the embossed gold numerals and markers are subject to wear and separation after seven decades. The silver dial itself can develop patina unevenly, and any previous moisture intrusion will show up there first. These were sold both on strap and on bracelet, so original-configuration examples with matching hardware carry added interest for collectors focused on completeness.
From the Catalog
Hamilton marketed the Datomatic A as a stainless steel, waterproof, self-winding, shock-resistant watch with sweep seconds, priced at $65.00 in 1955. The 1954 catalog listed it at $71.50 on strap or $79.50 with bracelet, reflecting the added cost of that configuration.
Hamilton Catalog Images
1954
1955
What to Look For
| Dial | Look closely at the embossed gold numerals and markers under good light. Separation, losses, or uneven silvering on the dial surface are the main condition concerns here. The date window cutout is also worth checking for chips or previous amateur finishing. |
| Crystal | The original crystal would be acrylic. Check for deep scratches or crazing, which can distort the dial read and suggest the watch has had a rough life. A clean replacement is far preferable to a badly damaged original. |
| Movement | Ask about service history. In a caliber 1258 that has gone years without attention, dried oil creates enough friction to stop the rotor from winding effectively or the movement from running at all. A recently serviced example is worth the premium. |
| Case | The stainless steel case should show honest wear consistent with its age, not heavy polishing that has softened the original lines. Check the caseback for signs of forced opening, which can leave tool marks or damage the threads. |
| Crown | Confirm the crown winds and sets the time and date smoothly without slipping or grinding. A worn or replaced crown on a watch this age is common, but a proper-fitting original or correct replacement matters for the overall integrity of the piece. |
The Movement
The ETA caliber 1258 is a Swiss-made 17-jewel automatic, wound by a rotor that transfers motion through a bidirectional winding mechanism. It drives a date complication in addition to the sweep seconds hand visible through the dial. ETA movements of this generation are well-regarded for their reliability, though like any vintage automatic that has sat unserviced, dried lubricants can create enough friction to bring the movement to a stop.