Accumatic
1956–1958 · Stainless Steel · Automatic
About the Accumatic
The Accumatic is where Hamilton's automatic story begins. Introduced in 1956 and produced through 1958, this was the first model to carry the Accumatic name, which would go on to define a full family of Hamilton automatics spanning into the 1970s. It runs on the caliber 672, a 17-jewel automatic movement that also accepts hand winding, and it came in stainless steel with either a white or black dial. Hamilton offered it on a bracelet or strap, with three distinct dial configurations at launch.
Finding an original Accumatic in honest condition is satisfying, mostly because the dial options give each example its own character. The embossed silver numerals and markers have a subtle texture that reads differently depending on light angle, and the leather texture dial variant is the one worth hunting for specifically. Condition of the embossed detailing is worth scrutinizing closely, as worn examples can lose that crispness that makes these dials interesting in the first place.
From the Catalog
Hamilton positioned the original Accumatic as a waterproof automatic in stainless steel, offering buyers a choice of dial style and whether they wanted a bracelet or strap. On a strap, the retail price was $65.00 at launch; the bracelet version added a few dollars to that.
Hamilton Catalog Images
1956
1957
1958
What to Look For
| Dial | Check the embossed numerals and markers carefully. The raised detailing can collect grime or show wear in ways that flat printed dials don't. On the leather texture variant, look at the overall surface consistency. Any bubbling, separation, or discoloration around the numeral bases is worth flagging. |
| Crystal | These left the factory with acrylic crystals. Scratches are common and expected on unrestored examples. A replacement acrylic in the correct profile is an easy fix, but make sure the profile matches the original dome height. |
| Movement | The 672 is a capable movement, but dried lubricants are the most common issue on unserviced examples. A watch that ticks but stops after a few hours is a classic sign of oil breakdown. Ask whether it has been recently serviced. Also worth knowing: the rotor engages when the crown is used to hand wind, which is normal behavior for this caliber. |
| Case | The stainless steel case holds up well, but the case back can be stubborn to open. The slots in the ring are narrow and don't always play nicely with standard case wrenches, so evidence of slipping or marring around the case back edge can indicate someone forced it. Inspect that area carefully. |
| Crown | Original crowns are often replaced. Check that the crown matches the case finish, pulls smoothly through its positions, and doesn't feel loose or wobble. A mismatched or oversized crown can be a sign of a previous repair using whatever was on hand. |
The Movement
The caliber 672 is an ETA-based 17-jewel automatic that Hamilton used to power the first generation of Accumatic models. It winds automatically via a rotating rotor as the watch moves on the wrist, but it can also be wound by hand at the crown. It's a reliable workhorse of a movement with good parts availability, though like any watch from this era it benefits from a fresh service if it hasn't seen one in the past several years.