MIL-W-46374B, published 7 May 1975, added the requirement for the H3 and radiation symbol to the dial, "centrally located and clearly visible". Revision B also broadened and deepened the requirements for handling, applying, and disposing of Tritium, and watches containing Tritium. These "B" type watches were the first required to have "Dispose Rad. Waste" inscribed on the caseback.
Also new was the requirement for a durable protective clear coating on the hands. This explains why the tritium luminous material on the "B" type watches seems to stay adhered to the hands much longer than on earlier versions.
The watch strap (specified as a Type II MIL-S-46383B strap) was to be Olive Drab in color. As with earlier specifications in this series, the bars were required to be fixed or "integral". Spring bars are specifically excluded.
Used with permission of Ned Frederick