What tolerances can be achieved for gear pitch and bore alignment?
What Tolerances Can Be Achieved for Gear Pitch and Bore Alignment?
Importance of Tolerance Control in Gear Manufacturing
Precision in gear pitch and bore alignment is critical for minimizing backlash, noise, and wear in gear-driven assemblies. At Neway Die Casting, we achieve high dimensional accuracy through a combination of high-quality die design, stable alloy casting, and precision CNC post-machining, ensuring gear performance that meets ISO and AGMA standards for both industrial and compact gear systems.
Achievable Tolerances for Gear Features
Feature | Typical Tolerance Achieved | Standards Referenced |
|---|---|---|
Gear Pitch (P.C.D.) | ±0.02–0.05 mm | AGMA 8–10 / ISO 1328 Grade 7–8 |
Circular Tooth Thickness | ±0.015–0.03 mm | AGMA 8+ |
Bore Diameter | ±0.01–0.025 mm | ISO H7/H8 class fits |
Bore Concentricity | ≤0.02 mm | Relative to gear pitch circle |
Face Runout | ≤0.03 mm | Measured from gear face to bore |
Tooth-to-Tooth Variation | ≤0.015 mm | Profile error within ISO spec |
These values are achieved in materials such as C85800 free-cutting brass, C87850 silicon brass, and Brass 464.
Tolerance Control Methods at Neway
High-Precision Tooling: Gear cavities are cut using EDM and high-speed CNC to control profile and tooth spacing.
Post-Machining Finishing: Bore diameters, keyways, and mating surfaces are machined to tight tolerances using multi-axis CNC systems.
CMM and Optical Gear Measurement: Used to measure pitch, runout, and profile variation against AGMA and ISO tolerances.
Automated Runout Correction: Secondary operations realign gear faces to ensure concentricity to the bore for rotating assemblies.
Typical Applications Requiring Tight Gear Tolerances
Miniature gearbox gears (robotics, HVAC actuators)
Transmission pinions in automotive valve controls
Precision worm gears in motorized instruments
Spur and bevel gears in consumer mechanical products
Standards We Adhere To
AGMA 2000-A88 / AGMA ISO 1328-1 – Gear tooth accuracy and profile grading
ISO 2768-f – Dimensional tolerances for machined features
DIN 3962 – Surface finish and profile deviation standards for gear manufacturing
Customer-Oriented Gear Manufacturing Services
Neway Die Casting provides fully integrated gear solutions, combining casting precision with secondary machining:
Brass Die Casting: Ideal for small, high-precision gears with tight tolerance requirements
Post-Machining Services: Final bore, pitch, and alignment control for rotating gear components
Tool and Die Making: High-accuracy cavity design for gear profile stability and tool longevity
