Knife bayonet

Spike bayonets proved useless when separated from the rifle and ineffective in trench warfare; and while versatile, sword bayonets proved to be impractical weapons in trench warfare because of their overall length.

The first knife bayonet to see widespread service was the 10 inch (25.4 cm) blade Seitengewehr 1871/84, which became the standard German infantry bayonet in 1884.

The knife bayonets are basically fighting knives or utility knives with a lug and/or muzzle ring to attach to the barrel of a firearm such as an assault rifle, submachine gun, or combat shotgun.

Some have serrated back edges to enhanced its cutting utility and to be usable as wire cutters (when used in conjunction with fittings on the sheath).

They have been tempered for durability so as not to bend or break when twisting; this was often the problem with long and slender spike bayonets.