Aluminum-Bronze Screw Gears
Precision grade JIS grade N9 (JIS B1702-1: 1998) JIS grade 5 (JIS B1702: 1976)
section of gear Normal plane
Gear teeth Standard full depth
pressure angle 20°
Helix angle 45°
① When mating screw gears made of the same material they may cause abrasion and scoring. It is recommended to mate Screw Gears composed of different materials.
② The allowable torques shown in the table are the calculated values according to the assumed usage conditions.
③ The backlash values shown in the table are the theoretical values for the backlash in the normal 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 opposite hands (RH and LH) of helical gear sets.
⑤ If the bore diameter is less than φ 4, then the bore tolerance class is H8. If the bore diameter is φ 5 or φ 6, and the hole length (total length) exceeds 3 times the diameter, then the class is also H8.