Precision grade JIS grade N9 (JIS B1702-1: 1998) JIS grade 5 (JIS B1702: 1976)
portion of gear Normal plane
Gear teeth Aluminum-Bronze Screw Gears Standard complete depth
pressure angle 20°
Helix angle 45°
① When mating screw gears made of the same materials 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 based on the assumed usage conditions.
③ The backlash values demonstrated in the table are the theoretical values 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 create a set of screw gears. For parallel shaft applications,
mesh reverse 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 φ 5 or φ 6, and the hole length (total duration) exceeds 3 times the diameter, then the class is also H8.