Specifications
Precision grade JIS grade 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 CAC702
â‘ When mating screw gears made of the same material they may cause abrasion and scoring. It is recommended to mate Screw Gears made up of different materials.
② The allowable torques proven in the table are the calculated values according to the assumed usage conditions.
③ The backlash values shown in the table will be the theoretical ideals for the 
backlash in the normal direction of a pair ofidentical gears in mesh.
â‘Ł For offset shaft applications, match a RH with a RH, or LH with a LH, to produce a group of screw gears. For parallel shaft applications,
mesh reverse hands (RH and LH) of helical gear sets.
⑤ If the bore Aluminum-Bronze Screw Gears diameter is usually significantly less than φ 4, then your bore tolerance class is certainly H8. If the bore diameter can be φ 5 or φ 6, and the hole length (total duration) exceeds three times the diameter, then your class can be H8.