In knife manufacturing, heat treatment and sharpening are key processes. If the sharpening is not correct, no matter how thorough the heat treatment process is, the blade will always be inferior.
In the grinding cell, the blade is processed into its final shape. Finishing operations such as polishing, serration, and or surface treatment usually follow.
For many years, Mora’s knife manufacturers had to manually sharpen each knife on large whet grinding stones. Achieving a flawless finish required both skill and precision, as well as the ability to produce large numbers.
The Frosts, for example, used seven stone grinders. A skilled stone grinder could sharpen about 900 knives in a day. Grindstones were not always easy to come by.
During the First World War (1914-18), grindstones were hard to come by. You could buy some grindstones from a recently closed company in Älvdalen (Långö Liebruk). However, the stones were wider than those usually used, so they had to be split into three sections with a special rock saw.
During World War II, it was difficult to get new grindstones during the war because there were no boats going. KJ Eriksson’s Knife factory, for example, bought used whetstones from Frosts that were already worn out. However, there would still be some wear left on the stones.
The former employee at KJ Eriksson’s Knife factory, Ek-Axel, used a special tool to wear down the stones to the appropriate diameter. There was a lot of dust in the grinding room when the grinding wheels were torn, and it was a very physically demanding job. Sometimes overly hard or unevenly hard stones prevented them from grinding effectively.
According to Bo Eriksson, former CEO at Morakniv, the grindstones had diameters of up to 1200 mm. Sometimes the workers increased the speed to get better performance, but then the stone risked cracking and parts of it could fly around and workers could be injured.
At the beginning of the 2000s, picking machines and robots began to increasingly take over the heavy and monotonous grinding work.
Tool used for leveling and re-shaping the grindstone
Sven Rombin, KJ Eriksson, 1960s.
The same grinding stone that Sven Rombin used is still at the factory for display today.