ActOn Case Studies

Metal Polishing and Surface Finishing Aerospace Gears

In the aerospace industry, precision and quality are non-negotiable. Components such as bevel gears play a critical role in aircraft performance, requiring exceptional surface finishing and metal polishing to ensure efficiency and longevity. A major aerospace manufacturer approached ActOn Finishing with a challenge—enhancing the surface quality of bevel gears from 0.4/0.5 Ra to 0.1 Ra while achieving a bright, shiny polish. Through a three-stage finishing process, ActOn successfully met the stringent requirements, ensuring the gears complied with aerospace industry standards.

Project Background

Bevel gears are essential components in aerospace applications, responsible for transmitting power at varying angles. To maintain optimal functionality, these gears must have a smooth surface finish with minimal roughness. The manufacturer sought a high-precision finishing process that would improve the surface roughness while maintaining part integrity.

The challenge was to reduce the surface roughness (Ra) from 0.4/0.5 to 0.1 microns and provide a highly reflective, polished finish. Given the tight tolerances required in aerospace applications, the solution had to be efficient, repeatable, and reliable.

The Aim

The goal was to implement a solution that would:

Ensure precise burr removal for smooth, sterile surfaces.
Maintain consistent thickness for control and stiffness.
Achieve scalable, high-volume production.
Reduce customer’s current process time.
Minimise environmental impact and waste.

To achieve these goals, ActOn designed a customised three-stage finishing process, incorporating grinding, smoothening, and polishing stages.

The Trials

To determine the most effective finishing approach, ActOn conducted free trials using different equipment, media, and compounds. The trials were carefully monitored to measure surface roughness and visual appearance at each stage. The goal was to create a cost-effective and time-efficient process without compromising the quality of the finish.

After multiple test runs, ActOn finalised a three-stage finishing process that provided optimal results while maintaining part integrity and aerospace compliance:

Stage 1 – Grinding

Equipment: Drag Finishing Machine
Media: Abrasive ceramic media
Compound: Multi-purpose liquid for cleaning ferrous metals (with a strong corrosion inhibitor)
Process Time: 2 hours

This stage helped to remove machining marks, reduce the roughness significantly, and prepare the surface for the next phase.

Stage 2 – Smoothening (Chemcut Process)

Equipment: Vibratory Finishing Bowl
Media: Polishing ceramic media
Compound: Chemcut compound (produces a super smooth surface ready for polishing)
Process Time: 4 hours

To achieve a super smooth surface, ActOn adapted the Chemcut process, which enhances material removal while preserving component precision. This step further reduced Ra values and prepared the gears for polishing.

Stage 3 – Metal Polishing

Equipment: Vibratory Finishing Bowl
Media: Polishing ceramic media
Compound: Polishing compound
Process Time: 2 hours

In the final metal polishing stage, the gears were processed to achieve a bright, mirror-like finish while maintaining the required Ra values. The polishing ceramic media, combined with a specialised polishing compound, ensured optimal reflectivity and smoothness.

The Result

ActOn successfully met the project’s objectives, delivering outstanding finishing results for the aerospace manufacturer:

Achieved the required Ra value of 0.1 – 0.11 microns.
Bright, mirror-like polished finish on all bevel gears.
Efficient, faster and repeatable process suitable for large-scale production.
Enhanced corrosion resistance due to specialised cleaning and protective compounds.
Preserved critical dimensions and tolerances, ensuring the gears remained within aerospace industry standards.