[M8×18]
■ Head Shape: Small Hexagonal P=3
This is an integrated screw with a hex head that is smaller than normal and has a spring washer (spring washer) and a JIS standard flat washer (round washer) on the head seat.
Use a tool such as a spanner or wrench to tighten it.
■ Thread Shape: Coarse
It is the most standard pitch in Japan as prescribed by ISO (International Organization for Standardization) standard. The most frequent distribution in Japan.
■Material: Iron
"Iron" is "steel" and is an alloy of iron containing carbon.
Although it is commonly used in many circulations, it is cheap materials, but due to the downside of it is easy to rust, many surface treatments will reduce corrosion.
■Surface treatment: Trivalent black
It has the same corrosion resistance as the "black chromate" and has the same possibility of self-healing.
Unlike hexavalent chrome, it is non-toxic and compliant with RoHS directive. Therefore, it is used as an alternative to black chromate.
Color is "Black".