MIL-W-46374E arrived on 31 May 1989. This revision brought the most dramatic changes in the face of military watches in decades. The font used to display numbers on the dial was changed to a more contemporary, and, I think, less legible style. If you look at the figure Old School v. New School, you will notice the differences right away.
The new font has serifs, little extensions on the base and top of the "1" for example, and the three has a rounded rather than a flat top. Serif style characters make lines of text more readable because their horizontal elements help direct your eye along each line of text. But they are not as legible when applied as they are here on a watch dial. Another change is the switch from Tritium paint to Tritium vials with the E revision. A totally new dial look is created by the combination of the new font and the new dial layout required when Tritium vials are used in place of the luminous triangles of previous revisions. This dial design is particularly "techie" looking as it is interpreted by SandY with the "Peek-a-Boo" windows to reveal the Tritium vials. You can also notice the change in the shape of the hands prompted by the use of Tritium vials instead of paint. The vials would not fit in the broad sword style hands of the "D" and earlier revisions, so a new shape that would accomodate long vials was designed.
OLD SCHOOL V. NEW SCHOOL
In the dark, the Tritium vial system (E Type and beyond) is superior. In fact, most people rave about the brightness and legibility of the Tritium Vial watches at night. I can even read by the glow of my Sandy P650 when my eyes are dark adapted! But, when trying to get a quick read of the time, or, in dim light, when it's not not dark enough for the Tritium to kick in, I prefer the old style dial and hands - especially on the "D" revision watches. I think they are much more legible. What is your impression when you compare the two dials shown above?
In addition to the dial layout changes the "E" revision calls for interchangeability of all parts on Type I watches on the same model from the same maker. The requirement of less than 25 milliCuries of radioactive emission from the watch face was also added to this specification.
The caseback markings on the MIL-W-46374E watches followed the specified 11 line pattern shown below. In the info page for the W-46374B revision, we described what several of these inscriptions mean in detail. The only significant change here is the requirement for specific Nuclear Regulatory Commission information to be on the caseback. Type 1 watches use the date of acceptance by the DoD. All other types use date of manufacture.
Caseback Markings US-Issue MIL-W-46374E SandY 490
The SandY 490 is one of the higher quality MIL-W-46374 watches ever issued, despite the "cheap plastic" first impression. Olive colored "E" type SandY 490's were issued in the early 1990's. They have a high-beat, maintainable and adjustable ETA movement. The Black "F" type SandY 490 was issued later, and is very similar in construction and reportedly shares the same movement. These SandY 490's sell for a typical price of $100 to $120 for New In Box versions.
What is most collectable about the SandY 490 with the MIL-W-46374E specification is that it is the first issue with the new dial design. Also, it is one of only a few "E" revision watches ever issued. Marathon supplied a few Type 2 and Type 3 MIL-W-46374E watches in 1991. All with the same dial design. The main difference between the SandY and Marathon dial is the way the Tritium vials were used. On the Marathon watches they are arrange like spoke ends on the hour marks, whereas with the SandY layout (see images of both dials below) they are oriented perpendicular to the radial arrangement of the Marathon dials and only revealed through holes in the dial along the chapter ring.
TWO WAYS TO USE LUMINOUS TRITIUM VIALS
The popular "F" revision followed quickly on the heels of these few "E" revision issues, appearing in October 1991. This meant that the "E" revision had a short lifespan of a little over two years - a blink of an eye in the world of Mil Specs. Examples of the various MIL-W-46374E watches should appreciate in value over the years, because of their relative scarcity.