In July 1950, the war technology department proposed, with concrete prototypes, introducing a new soldier's knife into the army, which later became known as the Model 51. They had been working on it for a long time. The most important difference to the 08 model was that the tools were all made of stainless steel. This has been used in pocket knives since the mid-1920s. As early as 1926, the idea of having soldiers' knives made of rust-resistant steel was considered. At that time, however, the additional price seemed too high on the one hand, and on the other hand people were skeptical as to whether this rust-resistant steel was actually suitable. In the meantime, experience had been gained that soldiers' knives made of stainless steel, which were made by the manufacturers for the retail trade, worked well and did not entail any loss of quality.
It is not clear from which manufacturer these specific prototypes came. These may have come from Wenger Delémont, as only Wenger supplied the new soldier's knife in the first year of production, 1951.
The proposed soldier's knife was about 1/3 lighter than the 08 model and 7 mm smaller. This proposal was developed specifically for the army. There weren't already existing models like the later model 61, which were like this or very similar on the market. Compared to the 08 model, the screwdriver had a notch for stripping cables. This was what the engineer troops had requested. Important criteria in the assessment of whether this newly presented soldier's knife was suitable or not were, on the one hand, the wear and tear in use and, on the other hand, the maintenance of the soldier's knife. This new soldier's knife was put through its paces before it was introduced. For example, 650 cans were opened with a can opener and no major stress was found afterwards. However, when testing the prototypes, it turned out that the proposed screwdriver was too wide, which caused problems when disassembling the new carabiners. Another suggestion was to increase the size of the rivet for attaching the screwdriver, as this was often used as a lever tool on duty and on the 08 model it could cause the grip liners to lift. There was also the suggestion of installing a safety device on the screwdriver so that it did not close unintentionally.
The feedback from the individual troops of the army was very different. The medical department, for example, wanted a different kind of soldier's knife for the nurses and the FHD women's welfare service, which had scissors instead of a screwdriver, and they preferred the version with a hollow rivet to the bail, so that the soldier's knife could be attached to a cable or chain. Consideration was also given to using plastic scales instead of the red fiber scales. Since around 1937, celluloid/ cellidor has been successfully used in place of fiber sheaths in so-called army knives. The problem there, however, was that there were still large amounts of fiber left over, which obviously wanted to be used further. The senior medical officer said that testing the new type was very suitable from his point of view. In particular, the tools made of stainless steel were praised. It was stated that the soldiers hardly needed the model 08 soldier's knife in everyday life for fear of an inspection, since it always had to be tiptop there. That's why it was better not to use it at all, or to buy a second copy. The Oberfeldarzt was less happy with the reduction in size, since normal soldiers would prefer the size of the 08 model. However, the size of 93 mm is very suitable for the FHD.
It is known that special prototypes have been developed and tested for the women's welfare service. These included 3-layer pocket knives with an additional layer of scissors. An order quantity of approx. 10,000 pieces and an additional price per piece of CHF 1.90 were expected. Although the testing went well, there was ultimately no definitive order. The reasons are unclear. The maintenance effort and the additional costs were probably too great to justify such a special order. Finally, in March/April 1951, they were ready to definitely order the new Model 51. Only Wenger Délemont did deliver in 1951. Victorinox got involved in 1952.
Model no. 151 was produced by Victorinox between 1952 and the 1960s. Unlike other models, Victorinox and Wenger jointly produced this model as a soldier's knife for the successor model to the Model 08 soldier's knife. Victorinox and Wenger supplied the Swiss Army with the model 151 between 1951 and 1960, with Victorinox not producing models no. 151 in 1951, 1958 and 1960 made for the Swiss Army, but only Wenger.
The advantage over the previous model 08 soldier's knife was the rust-resistant steel, which was used for the first time for soldier's knives, and the lower weight. The scales remained made of fiber. From 1954 model no. 151 received a different foot rivet. Otherwise, this model remained practically unchanged throughout the production period.
In addition to the official Swiss Army Knives with vintage and weapons control stamp, Victorinox also produced model no. 151 for the civilian market. These had no vintage stamp. Some of these were marked with a P for private on the back of the cutting blade. Like the previous model 08, the model 51 could be ordered and purchased with or without a weapons control stamp.
The model no. 151 could still be bought as a civilian version years after the Swiss army was no longer supplied.
Model No.151 had a large cutting blade, can opener, awl, and screwdriver.
Big cutting blade: 2.75 mm; Screwdriver: 2.7mm; Awl: 1.8 mm; Can opener: 2.7 mm; Tubular rivet for can opener and awl: 3.6 mm; Rivets for screwdriver and cutting blade: 3.1 mm; liner. 1.3mm
Model No.151 had 2 plies and 4 tools. Large cutting blades and screwdrivers moved around the head rivet, and the awl and can opener around the base rivet. Model No.151 never came with a toothpick/tweezers or hanger.
Victorinox used brown fiber as the material for the scales.
Model No. 151's liners and liner were made of German silver, and the rivets were made of steel.
Trade names: Soldier, soldier 's knife