Draft:UTON vz.75

In the early 1970s, the Czechoslovak military sought a replacement for the ageing VO-7 airborne knife. Development was assigned to workers at Research Institute 010 in Slavičín in cooperation with the knife manufacturer Mikov of Mikulášovice. The project was given the codename UTON (an acronym of Útočný nůž, "assault knife").

Development concluded in 1973 with successful military trials. On 15 December 1976, the technical conditions TP-VD-648-76 for the production and acceptance of the assault knife vz. 75 were officially approved.^[1]

The knife entered serial production at Mikov and was issued primarily to reconnaissance, airborne and aviation units of the ČSLA, who carried it on the reserve parachute harness for use in emergency situations such as clearing parachute malfunctions. It was packaged in cardboard boxes of ten, together with a sharpening stone, and stored coated in preservative grease type P.

The UTON vz. 75 was gradually superseded by the Bonus vz. 85 from 1985 onwards. However, it was never fully withdrawn from service and remains in limited use at some Czech Army units, with most units having adopted unit-specific commemorative knives or the bayonet of the CZ BREN assault rifle, which also functions as a knife.

The UTON vz. 75 is a robust single-edged fighting knife with a clip point blade featuring a false edge on the spine. The blade is manufactured from stainless steel grade 17029, heat-treated using the MARTFROST process (deep cryogenic treatment after hardening) to a surface hardness of 50–58 HRC. The blade surface was ground to a roughness of 0.2–0.8 Ra to reduce light reflection.^[2]

The handle is moulded from rubber compound 137.21, manufactured by Gumokovov of Hradec Králové, and pressed directly onto the blade tang. Two metal plates are riveted to the tang before handle moulding to reinforce the rear section. The handle features a cross-hatched grip pattern on the sides, a slot in the rear for the file and saw accessories, and a 6 mm hole for the locking brass pin.

The leather sheath is constructed from five layers of natural cowhide, sewn together and secured with brass rivets. It includes front pouches for the file and saw, a rear pouch for the safety cord, and two internal steel spring plates to retain the knife securely.

Before acceptance into service, the UTON vz. 75 underwent extensive testing at the VZS 080 laboratory, documented in protocol no. 1286/76. Key results included:

• Blade-to-handle joint strength: The rubber handle withstood a tensile force of 2,000 N (approx. 200 kg) on the ZWICK testing machine without separation.
• Blade flexibility: Required to withstand bending to 5° in both directions without permanent deformation.
• Edge durability: Required to withstand 500 cuts into hardwood and still pass a sharpness test.
• Edge sharpness: Required to sever a 2 m parachute cord loaded with a 2 kg weight in a single cut.
• Corrosion resistance: Required to withstand exposure to sulphuric acid vapour.

Tests revealed that blade fractures during bend testing consistently occurred at the location of the stamped series number, due to a notch effect in the steel. The protocol recommended repositioning the numbering to the centre of the blade and stamping it longitudinally.^[2]

Beyond the standard military production series, a number of commemorative and gift versions were produced by Mikov for individual units and occasions, including editions for the 601st Special Forces Group, URNA (Czech police counter-terrorism unit), the SFOR peacekeeping mission, and various anniversary editions for airborne units. A civilian version was also produced commercially, distinguished by the series number stamped on the left side of the blade and a matte rather than polished rubber handle.

• Czechoslovakia — Czechoslovak People's Army (1976–1993)
• Czech Republic — Army of the Czech Republic (1993–present, limited)
• Slovakia — Armed Forces of the Slovak Republic (1993–present, limited)

• Bonus vz. 85
• VO-7
• Mikov
• Czechoslovak People's Army