MIL-W-46374

MIL-W-46374 is a specification first published on October 30, 1964, for US military watches. The 46374 was specified as an accurate, disposable watch. In its span, it encompassed metal and plastic cased watches with both mechanical and quartz movements. The 46374 replaced the MIL-W-3818, reducing cost and inheriting the dial from the MIL-W-3818B. These were lower quality watches than the 15 jewel movements, the transition started as US involvement in Vietnam ramped up.
Revision A was released in 1968. Regarding Revision B from 1976, it "added radiation symbols to the dial, indicating that the luminous markers were radioactive, H3 for tritium. Revision D (1986) expanded the scope of the specification to encompass a wider range of watches."
Pilots, divers, and other specialties continue to have military watches available for issue.
Dial font.
In 1957 the DOD released MIL-C-18012A, a specification detailing the legibility of numerical displays for aircraft dials and readouts, and updated it with MIL-C-18012B in 1964. At the same time as 18012B was released, so was 46374. The font 46374 inherited from W3818B is unique, "It borrows elements from the super legible Futura and Gothic style fonts of the day but it is mostly influenced by the numerical font shown in MIL-C-18012A (This font itself borrowed heavily from the Grotesk fonts of the 1920s - later known as the German DIN fonts of the 1970s). Look particularly at the flat-topped "3" and the simple geometric shapes of the other numbers. Although the numbers used on the watches (both MIL-W-46374 and the earlier MIL-W-3818B) are more rounded and bolder, the only significant departure the watch designers seem to have taken is with the "9" and "6" which have rounded and more curved tails." Uncluttered, legible dial designs like the Waltham A-13, and the Chelsea Army Message Center Clock (Mark I) inspired the US Army’s Frankford Arsenal in Philadelphia who created the dial specifications and designs, and "The minute hand in the Mark I Chelsea seems to have lent a strong influence to the hand designs used in MIL-W-3818B watches."