Ikeda Industries has developed stainless steel screws that are dyed blue, yellow or red by oxidative coloring. These screws are designed to detect foreign matter contamination at the food production site at an early stage and to prevent shipment of goods in a contaminated condition. In the assembly of food manufacturing machinery, stainless steel screws because of its corrosion resistance has been widely used, but this screws once loose and fall off, mixed into the milk, mayonnaise or other white food, it is difficult to find them. In fact, there have been cases where screws have been mixed into packages that were shipped without their knowledge.

To solve this problem, Ikeda Metals has developed a special surface principle called "stainless steel oxidation coloring" for stainless steel screws to comply with the Food Sanitation Law. By easily identifying the color of the screws, even if they are mixed with food, it is possible to detect foreign matter contamination at an early stage and prevent shipments in a mixed state.