The Professional Series from Kemper Tools are made from high carbon knife-quality steel that has been heat treated and quenched in oil to give the blades maximum hardness and durability. Because high carbon steel takes and holds a much sharper edge than stainless steel, they are able to tackle even highly-grogged clays and plaster. The steel blade is firmly set into the brass ferrules with an industrial adhesive. The handles themselves are immersed in an oil resin bath to seal the handle against water damage and prolong the life of the tools.
The tool is durable, but not indestructible. Keep tools clean and dry when not in use. Do not leave tools soaking in water or slurry for extended periods of time. Periodically apply a light coat of oil to the both the blade and handle. Sharpen using an oil or water whetstone. Do not sharpen using a file. Do not sharpen with a power grinder. This will heat the steel, which changes the temper and destroys the tool.