Bomb fuzes are yet another interesting sub-set of militaria collecting. There are hundreds of designs but Japanese aerial bomb fuzes have a style and character that sets them apart from fuzes of other nations.... almost art forms. For the mechanically minded, there are lots of interesting details to be observed. As with many other ordnance related militaria items, the more interesting bits and pieces are sometimes discarded when demilled, or just get lost along the way, so finding intact examples can present a challenge.

For reference material, probably the single best source of readily available information is the U.S. Department of the Army Technical Manual TM 9-1985-4, which was the primary source of information for this article. The TM 9 series of publications is a great reference for all sorts of ordnance related items. While original copies have become collectable items in themselves, reprints are available through on-line sources.

For the collector, determination as an Army or Naval fuze is a useful tool for quick identification. Army Air and Naval Air branches were separate and distinct. Bomb fuzes as well as bomb casing designs were specific to either service. There are basic functional differences and the fuzes were not designed to be interchangeable.

The Japanese Army Air Force used safety forks inserted over the fuze top. So holes are often in evidence in the air vanes. Primer componets were integral to fuze and factory installed.

Naval bomb fuzes have safety forks and pins inserted from the side. Primer components are typically housed separately from the fuze body in separate fuze gaines. This allowed munitions to be configured for specific targets. For example, a bomb might have the fuze delay time increased for detonation deep below decks, or a short delay might be selected for a surface burst.