Ricoh Humming 19 Calendar – Mechanical Ladies' Watch in Tank Case

A rectangular case with a diamond-cut edge, a mechanical movement with 19 jewels and a date – all in a watch measuring just 19 millimeters in width.

The case back is stamped with RICOH, S.P. STAINLESS BACK, model number 7424, and the number 816792.

Ricoh as a Watch Manufacturer

Today, Ricoh is primarily known as a manufacturer of cameras and office equipment. From the 1960s to the 1980s, the company also operated its own watch production line, which competed directly with Seiko, Citizen, and Orient on the Japanese domestic market.

The "Humming" line belonged to the premium segment of this program. Ricoh watches from these years are interesting to collectors because they document a fourth, largely overlooked path in Japanese watchmaking – one that barely existed on the European market and whose models rarely appear here.

The movement operates with 19 jewels and a date display. Nineteen jewels is a high value for a watch of this size; ladies' movements from these years often made do with significantly fewer.

Please note: The case back is marked as "S.P. Stainless Back." Only the back is made of stainless steel; the case itself is plated.

Design

The dial is silver-colored and features slender, applied baton indices; the double indices at 12 o'clock provide an anchor point for the strictly rectangular format. Below the center is the "Humming" lettering in script, as well as the words "19" and "Calendar." The date window is located at the bottom right.

The real appeal lies in the case design: the top and bottom edges of the case feature a continuous, diamond-faceted decor that refracts light in a series of small reflections. This finishing was elaborate and is rarely found on watches of this size category; it gives the otherwise sober tank format a decorative touch without tipping into playfulness.

At 19 × 26.5 millimeters and weighing 16 grams, the watch is exceptionally petite – dimensions that are once again in demand today.

Dating

The case back bears the model number 7424 and the number 816792. There is no publicly documented dating system for Ricoh watches from these years, so a precise year of manufacture cannot be determined. Case shape, dial design, and movement style place the watch in the 1970s.

Condition

The dial shows signs of age: there is discoloration and fine spotting in the upper right area and around the center of the dial, as is frequently seen on dials of this period. The applied indices are secure, the hands are complete and undamaged, and the date sits neatly in the window.

The crystal is clear and shows only light signs of wear. The case shows signs of wear and polishing; the faceted edge is intact all the way around and has not been buffed away. The case back is lightly scratched, but the engraving remains fully legible.

The watch has been fitted with a new, high-quality leather strap, reusing the original buckle – a detail that preserves the overall impression of the watch.

The actual condition is shown unretouched in the product photos.

Technical Data

• Brand: Ricoh
• Model: Humming Calendar
• Model number: 7424
• Case number: 816792
• Movement: mechanical
• Jewels: 19 jewels
• Functions: hour, minute, center second, date
• Case: plated metal with stainless steel back, rectangular with faceted edge
• Dimensions excluding crown: 19 × 26.5 mm
• Height: 10.3 mm
• Lug-to-lug: 34.1 mm
• Lug width: 15 mm
• Weight incl. strap: 16 g
• Dial: silver-colored with applied baton indices
• Strap: new, high-quality Japanese-made leather strap with original buckle
• Dating: 1970s
• Origin: Japan

Who is this for?

For those with slender wrists who find a width of 19 millimeters to be the perfect fit. For collectors of Japanese watches who look beyond Seiko and Citizen and want to add Ricoh as a fourth manufacturer to their collection. And for anyone looking for a mechanical watch where the dial patina is part of the watch and has not been retouched away.

Warranty (used)

This is a used item. The limitation period for claims for defects under the statutory warranty is 12 months from delivery.

Note on water resistance

The watch dates from the 1970s. Water resistance is not guaranteed. To protect the movement, the watch should not come into contact with water or moisture.