The Victorinox Metal Saw is manufactured with a special hardening process, and an additional hard chromium plating to produce a hardness capable of cutting iron. On each side of the saw blade is a metal file, one side is coarser than the other. The fine side is smooth enough to be used as a nail file in a pinch.
As with almost all metal files, the cut of Victorinox metal files was created on a file cutting machine with a chisel. Case-hardening steel is used for thinner files. The hardening process used on this steel makes its surface very hard while its core remains soft, thus helping to prevent breakage.
As case-hardening steel is not stainless, Victorinox files needed to be hard-chrome plated. Unfortunately, this process slightly reduces the sharpness of the teeth. In contrast to case-hardening steel, the teeth of files and saws made from stainless steel are ground on a high-precision machine. Changes to the geometry of the metal file have made it stronger. The performance of the file has also been improved.
In 2005 (date needs confirmation) Victorinox introduced a new Stainless Steel metal saw and file. This new tool can be very aggressive in removing material and should last a very long time if maintained.
On 91mm models, you can tell apart the old from the newer metal saws easily, by examining one of the following:
• On the old one, texturing stops 8mm away from the handle, whereas on the new texturing stops 2mm away.
• On the old one, the two diagonal file cut-grooves start individually, meeting up to create a V, and continue to create the cross-cut pattern, and separate at the tip. The new file is also cross-cut, but the two diagonal cut-grooves both start from the very beginning, giving the impression of a single-cut file, even though it is double-cut.