2-12
As you can see, the new military designation is much easier to understand than the old military
designation.
You may find a fuse coded in one of the commercial designations. The commercial designations are
fairly easy to understand and figure 2-10 shows the old and new commercial designations for the same
type of fuse that was used in figures 2-8 and 2-9.
Figure 2-10.—Commercial designations for fuses:
OLD COMMERCIAL DESIGNATION
Figure 2-10, view A, shows the old commercial designation for a fuse. The first part of the
designation is a combination of letters and numbers (three in all) that indicates the style and time delay
characteristics. This part of the designation (3AG) is the information contained in the style and time delay
rating portions of military designations.
In the example shown, the code 3AG represents the same information as the underlined portions of
F02 G 1R00 A from figure 2-8 (Old Military Designation) and F02A 250VIAS from figure 2-9 (New
Military Designation). The only way to know the time delay rating of this fuse is to look it up in the
manufacturer’s catalog or in a cross-reference listing to find the military designation. The catalog will tell
you the physical size, the material from which the fuse is constructed, and the time delay rating of the
fuse. A 3AG fuse is a glass-bodied fuse, 1/4 inch 1 1/4 inches (6.35 millimeters 31.8 millimeters) and
has a standard time delay rating.
