addition to 'limited edition' productions runs, numerous examples from basic to professional-level customizations of standard knives—such as retrofitting pocket clips, one-off scales created using 3D printing techniques, decoration using anodization and new scale materials—can be found by searching for "SAK mods". Assembly During assembly, all components are placed on several brass rivets. The first components are generally an aluminium separator and a flat steel spring. Once a layer of tools is installed, another separator and spring are placed for the next layer of tools. This process is repeated until all the desired tool layers and the finishing separator are installed. Once the knife is built, the metal parts are fastened by adding brass flanged bushings to the rivets. The excess length of the rivets is then cut off to make them flush with the bushings. Finally, the remaining length of the rivets is flattened into the flanged bushings. After the assembly of the metal parts, the blades on smaller knives are sharpened to a 15° angle, resulting in a 30° V-shaped steel cutting edge. From sized knives the blades are sharpened to a 20° angle, resulting in a 40° V-shaped steel cutting edge. Chisel ground blades are sharpened to a 24° angle, resulting in a 24° asymmetric-shaped steel cutting edge were only one side is ground and the other is deburred and remains flat. The blades are then checked with a laser reflecting goniometer to verify the angle of the cutting edges. Finally, scales are applied. Slightly undersized holes incorporated into the inner surface enclose the bushings, which have truncated cone cross-section and are slightly undercut, forming a one-way interference fit when pressed into the generally softer and more elastic scale material. The result is a tight adhesive-free connection that nonetheless permits new identical-pattern scales to be quickly and easily applied. Sizes Victorinox models are available in , , , , , , and lengths when closed. The thickness of the knives varies depending on the number of tool layers included. The models offer the most variety in tool configurations in the Victorinox model line with as many as 15 layers. Wenger models are available in , , , , and lengths when closed. Thickness varies depending on the number of tool layers included. The models offer the most variety in tool configurations in the Wenger model line, with as many as 10 layers. Knives issued by the Swiss Armed