The Mark I was expensive and time-consuming to manufacture, and reports from the field indicated that the knife's large "brass-knuckle" fingerguard handle made it difficult to secure in conventional scabbards while limiting the range of useful fighting grip positions.

[7][8] Another criticism was that the Mark I's thin blade was prone to breakage when used for common utility tasks such as cutting wire or opening ammunition crates and ration cans.

Shuey's pattern was essentially a copy of the Fairbairn–Sykes fighting knife with altered material specifications designed to reduce dependence on scarce metals.

The Marines of the 1st Raider battalion found it to be well designed for silent killing, but of little use for any other purpose, and too frail for general utility tasks.

[11] The Collins machetes,[12] which superficially resembled a large Bowie knife, were also issued to some Army air crews as part of the Jungle Emergency Sustenance Kit of 1939.

[1] Working with Union Cutlery, USMC Colonel John M. Davis and Major Howard E. America contributed several important changes, including a longer, stronger blade, the introduction of a small fuller to lighten the blade, a peened pommel (later replaced by a pinned pommel), a straight (later, slightly curved) steel crossguard, and a stacked leather handle for better grip.

[18][20] After the Second World War, the U.S. Navy and Marine Corps continued to use the Ka-Bar Fighting Utility knife.

[2] From 1945 to 1952, Weske Cutlery Co. of Sandusky, Ohio, purchased leftover and overrun parts from wartime knife contractors and assembled them for commercial sale, polishing out manufacturer and military markings, and fitting them with ungrooved leather handles.

[25][full citation needed] According to company records, the letter was only partially legible; "ka bar" could be read, as fragments of the phrase "kill a bear".

[18][29] The popular designation of the knife may also have resulted from contact with Marine Corps close combat instructors in San Diego, who used the name when training recruits.

Marines today often treat the blades, guards and pommels with non-reflective black spray paint to reduce reflected light and give them additional protection against saltwater corrosion.

[1] According to Ka-Bar, its 1095 Cro-Van, a moderate carbon and low chromium steel alloy, allows the blade to hold an edge very well.

In 1999, Ka-Bar released the "D2 Extreme" version of their fighting knife, coming with the same synthetic handle and sheath that was produced with the "Next Generation", but also a blade made from D2 tool steel for extra edge retention and slightly better corrosion resistance than 1095.