- Black oxide is a blue
gray-colored coating that combines good hardness in high heat with high
oxidation resistance. This coating has excellent wear resistance. Good
for use on ductile cast iron and mild and high carbon steels.
- Gold oxide
is a low temperature heat treatment which reduces grinding stress
within the tool, and has an appealing, easy-to-identify gold color. Gold
oxide is commonly used to identify cobalt steel tools.
- Uncoated (bright) tools have no
finish or coating. They are a common choice for general use