The Model No. 31 was produced by Victorinox between about 1930 and 1970. The knife was tooled very much like the Model No. 30, except that the curved blade was replaced with a small cutting blade. However, the structure was completely different. While the curved blade and the pocket awl formed the top layer on model no. 30 and the saw and corkscrew the bottom layer, on model no. 31 these were the large cutting blade and pocket awl for the top layer and the small cutting blade with the corkscrew for the lower tier.
Victorinox produced model no. 31 in sizes of 106 mm, 100 mm and 95 mm. Accableing to the 1964 catalogue, at that time model no. 31 was only available with tools made of stainless steel and horn scales. Other variants with carbon steel tools were available in previous catalogues.
In addition to a large cutting blade and a small cutting blade, model no. 31 had a saw, pocket awl and a corkscrew on the back. There was the model with the addition of a toothpick and tweezers and the option of a bail.
Big cutting blade: 2.5 mm – 2.8 mm; Awl: 2.0 mm; small cutting blade: 2.0 mm; saw: 2.0 mm; Corkscrew: 2.0mm
Model No.31 was a 3-layer model. Big cutting blade, small cutting blade and saw turned around the head rivet, the blind awl around the foot rivet and the corkscrew around the middle rivet. The upper layer consisted of the large cutting blade and pocket awl, the middle layer of the saw and the lower layer of the small cutting blade and the corkscrew.
Victorinox used red fiber scales and class I and II horn as the material for this pocket knife.
The rivets and liners were made of steel or brass, the jaws of nickel silver, depending on the version. In the case of the high-quality, so-called "fine version", rivets and liners made of brass and jaws made of nickel silver were used, and rust-resistant steel was used for the tools, if this was already available.