Chronomatic A
1971–1976 · Stainless Steel Chronomatic B
About the Chronomatic A
Made from 1971 through 1976, the Chronomatic A is a two-register chronograph powered by Hamilton's caliber 11, a self-winding movement built around the groundbreaking automatic chronograph mechanism developed jointly by Hamilton, Heuer, Breitling, and Büren in the late 1960s. The dial features a tachometer scale and a 1/5-second recorder track, giving this watch genuine utility for timing at speed rather than just decorative detail. The case is stainless steel with a round profile and straight lugs, a clean and purposeful shape that suited the sporting character of the chronograph line. The Chronomatic A is part of Hamilton's Chronomatic family, which represented the brand's push into automatic chronograph territory at a moment when that technology was genuinely new.
Finding a clean example means paying close attention to the pushers and the chronograph function itself, since these movements can develop quirks when they go too long between services. The tachometer bezel and recorder track printing on the dial are worth examining carefully under good light, as wear and fading on the scale markings are common on watches that saw real use.
From the Catalog
Hamilton described the Chronomatic A in 1975 as a self-winding two-register chronograph with a 1/5-second recorder track and tachometer scale, offered in stainless steel. The retail price at that time was $275.
Hamilton Catalog Images
1971
1975
1976
What to Look For
| Dial | Look closely at the tachometer scale and 1/5-second recorder track. Fading or loss of the printed markings is common and significantly affects both readability and value. Check the applied indices for any separation or corrosion at their bases. |
| Crystal | Inspect for deep scratches or crazing. A replacement crystal is often straightforward, but confirm the profile matches the original before buying. |
| Movement | Run the chronograph through a full cycle: start, stop, and reset. The reset function in particular can behave erratically on a caliber 11 that has not been serviced in some time. Dried lubricants in this type of movement create enough friction to cause the chronograph mechanism to hesitate or fail to reset cleanly, even if the base movement keeps running. |
| Case | Check the case back for tool marks from previous openings. Straight lugs on this generation of Chronomatic cases can show wear at the edges where straps were swapped, so look at the lug surfaces carefully. |
| Crown | Test the crown for smooth winding and positive engagement in the setting position. The water resistance rating this watch originally carried is not something to rely on at this age without a fresh pressure test and seal replacement. |
The Movement
The caliber 11 is an automatic chronograph movement, one of the first of its kind, developed through a collaboration between Hamilton, Heuer, Breitling, and the Büren movement company. It winds itself through a rotor and drives a two-register chronograph with a column wheel, which gives it a precise and tactile feel when operating the pushers. The movement is capable and well-constructed, but it has many components and benefits considerably from proper periodic servicing.