In helical and worm gears, the helix angle denotes the standard pitch circle unless otherwise specified. Application of the helix angle typically employs a magnitude ranging from 15 ° to 30 ° for helical gears, with 45 ° capping the safe operation limit. The angle itself may be cut with either a right - hand or left - hand orientation. In its typical parallel arrangement, meshing helical gears requires that the helix angles are of the same magnitude and cut oppositely.
for helical gear the helix angle generally ranges from
15 ° to 30 °