Specifications
Precision grade JIS quality N9 (JIS B1702-1: 1998) ＊ JIS quality 5 (JIS B1702: 1976)
Reference
section of gear Normal plane
Gear teeth Standard complete depth
Normal
pressure angle 20°
Helix angle 45°
Material Acetal 
Acetal is certainly a stable plastic material with inherent self-lubricating properties which can be enhanced with lubricating fillers.
Delrin Delrin can be an engineered plastic-type material with a good mixture of toughness, stiffness, use and abrasion resistance, and low frictional features.
Nylon Nylon, comprising a number of grades of polyamides, is a general-purpose material in wide use. It is hard and resistant and provides good pressure ratings.
Polycarbonate Polycarbonate is an extremely tough Plastic Screw Gears polymer which can be machined to close tolerances. Lubrication may also be needed, as the use properties of polycarbonate aren’t as good as various other polymers.
Other Plastic Additional unlisted or specific polymers or plastic components.