Original Item: Only One Available. This is quite possibly one of the rarest U.S. Military Fighting Knives in existence, and the very first we have ever had the pleasure of offering! These Underwater Demolition Team (UDT) Knives were made by a limited contract in 1961-1962 awarded to the Imperial Knife Company. Each and every one of these knives were issued to either Navy Frogmen, UDT team members, or Navy SEALs, with most being carried in Vietnam a few years later.

Only 1,156 of these knives were produced, and each unit was serial numbered. This particular knife is serial numbered 797.

Originally intended for Combat Divers to work around undersea Anti-Ship Mines, such as the Mk56, which were detonated magnetically. With this in mind, the U.S. Navy set forth designing a non-magnetic diver’s knife. These experimental knives were the result. They were an immensely expensive knife to produce at the time, costing the U.S. Navy $500 each in 1961, which is over $5,000 in 2023 dollars!

The Knife is made of Haynes Alloy no. 25 which is Copper-Chromium-Tungsten-Nickel Alloy, similar to Stellite. It is non-magnetic, non-sparking and non-rusting even in seawater, yet unlike many other non-ferrous metals like the titanium used in other high grade combat knives, it has the ability to be hardened to allow it to hold a cutting edge with a Rockwell “C” scale value of 53 to 54 which is per the final Naval specification. The specification also stated that the saw edge of the knife be capable of cutting through steel cable that the Diver may encounter on a mission. The Knife and Scabbard set had to pass a magnetic test of under 0.1 millioersted to be accepted per the Milspec.

Imperial supplied a total of 1,156 Non-Magnetic Dive Knives to the Navy with the first contract of 280 pieces being filled in March 1962 and continuing until the end of 1963.

The knife we are offering is in excellent condition, considering the rarity of these particular knives. It shows signs of honest use, with some sharpening to the blade. It is in what we would call “honest” condition, showing that it was actually used during its time of service. The knife is well marked on the top of the guard on both sides of the blade:

U.S.
NONMAGNETIC

Serial No. 797/61
IMPERIAL

This indicates that it was knife number 797 produced in 1961. The original plastic grips are in very good condition, only showing some light scratching and honest wear from use.

The Scabbard is marked on the throat U.S. / NONMAGNETIC / IMPERIAL. The scabbard shows equal amount of use, with some accumulated dirt/grime on the securing straps, and some wear to the belt loop from being carried. The sheath body itself has numerous surface scratches which are to be expected. The snaps and swivel all work perfectly.

Many of these knives were lost in Vietnam or are tucked away in museums and personal collections and it is one of the rarest collectible knives of the Vietnam Era. For additional information see Page 116 of Knives of the U.S. Military in Vietnam by M.W. Silvey.

One of the Rarest U.S. Fighting Knives to have ever been offered by IMA! Ready to display!

Specifications:
Blade Length: 7 3/8"
Blade Style: Spear Point Hollow Ground
Overall length: 11 7/8“
Crossguard: 2 1/2”
Scabbard Length: 8 1/8" with 4 3/4" Belt Loop