This article addresses some of the challenges that gear makers experience when they attempt to finish hob to a higher quality standard. A quality level that is higher than routinely expected in a production environment.
Gear blank factor:
Gear blank quality is another factor that can affect the lead variation. Gear mounting surfaces, i.e. bores and faces (for bore gears) or journals (for shaft gears), should be appropriately toleranced as those surfaces have a direct effect on lead quality.