Accumatic IV-B
1961–1962 · Stainless Steel · Automatic
About the Accumatic IV-B
Made from 1961 through 1962, the Accumatic IV-B is a stainless steel automatic from Hamilton's Accumatic family, running on the caliber 672 with 17 jewels and a sweep seconds hand. The Accumatic line was Hamilton's core automatic offering through the late 1950s and into the 1960s, and the IV-B fits within that group as a round-cased, bracelet-integrated model with two dial options. What makes it visually distinct is the embossed silver numerals and markers, luminous dots, and a pearled chapter track, giving the dial a layered, textured quality that photographs rarely do justice to.
Finding one in good shape means paying close attention to the dial, since the embossed numerals and markers can show wear at their edges after six decades of contact with moisture and cleaning attempts. Both the white and black dial versions turn up with reasonable regularity, though the black dial tends to attract more collector interest. The bracelet mentioned in the original catalog listing is almost never present on surviving examples, so a period-correct strap is usually the practical substitute.
From the Catalog
Hamilton listed the Accumatic IV-B at $69.50 in 1961, describing it as a stainless steel automatic with embossed white numerals and markers, luminous dots, and a pearled track on the buyer's choice of white or black dial, sold on bracelet.
Hamilton Catalog Images
1961
What to Look For
| Dial | Look closely at the embossed numerals and markers under good light. The raised edges are vulnerable to wear and flaking, and any loss of the silver finish there is hard to reverse without a redial. The luminous dots can discolor or shrink over time, which is normal, but they should be intact and sitting flat. Check for hairline cracks or separation around the 3, 6, 9, and 12 positions. |
| Crystal | The crystal should be clear and free of deep scratches or crazing. A hazy or heavily scratched crystal is easy to replace, but make sure the seller isn't using a cloudy crystal to hide dial damage underneath. |
| Movement | Oil dries out on movements this age, and even modest friction buildup can be enough to stop the watch entirely. The caliber 672 should keep itself wound from normal wrist motion, running continuously without needing to be manually wound just to stay going. Sluggish timekeeping or a watch that stops when set down overnight points to a movement that needs a service. |
| Case | The stainless steel case holds up well over time, but check the lugs for thinning from repeated polishing. The case back on these can be tricky to open since the slots in the retaining ring are small and don't accommodate a standard case wrench easily, so look for any evidence of amateur opening attempts, particularly gouging around the case back edge. |
| Crown | The crown should pull out cleanly and set the hands without slipping. On the caliber 672, manually winding through the crown engages the rotor, which is normal behavior, but the crown itself should feel positive in each position and screw or seat back in without wobble. |
The Movement
The caliber 672 is a 17-jewel automatic movement that winds itself through a rotor as the watch moves on the wrist. It is a reliable workhorse from Hamilton's American-era automatic lineup, straightforward to service and reasonably robust when maintained. Manual winding through the crown is possible but turns the rotor in the process, which is by design rather than a fault.