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