Specifications
Precision grade JIS grade N9 (JIS B1702-1: 1998) JIS quality 5 (JIS B1702: 1976)
Reference
portion of gear Normal plane
Gear teeth Standard full depth
Normal
pressure angle 20°
Helix angle 45°
Material CAC702
① When mating screw gears manufactured from the same material they may trigger abrasion and scoring. It is suggested to mate Screw Gears composed of different materials.
② The allowable torques shown in the table are the calculated values based on the Aluminum-Bronze Screw Gears assumed usage conditions.
③ The backlash values shown in the table are the theoretical ideals for the backlash in the normal direction of a set ofidentical gears in mesh.
④ For offset 
shaft applications, match a RH with a RH, or LH with a LH, to create a group of screw gears. For parallel shaft applications,
mesh opposing hands (RH and LH) of helical equipment sets.
⑤ If the bore diameter is significantly less than φ 4, then your bore tolerance class can be H8. If the bore diameter is certainly φ 5 or φ 6, and the hole length (total duration) exceeds 3 times the diameter, then your class is also H8.