Laboratory tests on mechanical steel and plastic gears

The extensive skills and equipment of Unilab Laboratori Industriali s.r.l. are at your service for the performance of laboratory testing on gears.


A gear is a toothed mechanical element, such as a shaft or a wheel, which rotates on its axis and couples to another toothed element to transmit a turning motion by modifying the speed and/or direction through well-known laws of motion. Gears are used in all applications in which power transmission is required, from the small mechanisms of a watch to the gears of gas turbines and the movements of operating machines (earthmoving and lifting machinery, power trains, etc.).

Industrial gears are complex elements owing to:

  • their vast range of usage applications they’re designed for
  • the materials they’re made from (steel, cast iron, aluminium, plastic, sintered powders, etc.)
  • their surface coating treatments
  • the complex geometries and contact trajectories (straight or helical teeth, cylindrical, bevel, and skew gears)
  • Their Quality standards (ISO, DIN, AGMA, JIS, BS, …)


These aspects illustrate the importance and need for advanced information both for the design and study of the functioning of these complex mechanical components.

Furthermore, a malfunctioning gear system can have dire consequences for the entire system it’s installed on (machine downtime, sudden breakages, further damage) with consequent economic costs that may exceed the cost of the mere components themselves by orders of magnitude.

The gear sector is progressively shifting towards the use of increasingly high-performance materials (special alloys, superalloys and loaded technopolymers), very high surface finishes, very low noise and vibration levels, and gears that can be adapted to specific operating temperatures. In addition, efforts are being made to increasingly reduce energy losses by optimising lubricant levels and reducing operating friction.

In car manufacturing, weight and noise are highly critical aspects, and this sector represents the primary market for Unilab’s laboratory, and the transition from combustion engines to electric motors is radically changing the gear transmission sector.

In Unilab, you can find technical analysis services specifically dedicated to these components, designed to help you both in the development phase of new projects and in the study of the behaviour of already existing systems.

Whether your company designs, manufactures and uses new products that use these components or a subcontractor working on designs provided by your clients, outsourcing services from a skilled, experienced and well-equipped laboratory can make a real difference.

Laboratory tests on gears – materials studies

Our laboratories can provide you with analysis of various aspects related to the performance of gears including:

  • the choice of the material and its resistance characteristics
    the performance of the surface coatings
    the quality of heat treatments
    Our laboratory can provide you with full information on the suite of services related to the study of gearing mechanisms


  • Conformity of supplied semi-finished products
    (bars, and forged and cast components, near-net-shape): this latter being defined as working processes that don’t require chip removal, including fine blanking, powder sintering, MIM and nowadays also 3D printing
  • Determination of the chemical composition, classification of the material and its characteristics at the microstructural level.
  • Analysis of heat treatments (surface and full depth)
  • Heat treatments.


What can we inspect in Unilab from a geometric point of view? Using Zeiss continuous scan measuring machines, equipped with a motorised IV axis, we can check the main geometries of the gears and certify compliance with the customer’s geometric specifications.

  • Tooth inspection– macrogeometry (before and/or after heat or surface treatment)
  • Profile inspection – microgeometry
  • Roughness inspection, based on the finishing process (grinding, electrochemical polishing, etc)

In the case of plastic gears, we can also inspect the macro geometry using tomography, with evaluation of injection defects and the study of the uniformity of the technopolymer (distribution, orientation of the reinforcing fibres).
We can also carry out evaluations of dimensions, geometry and roughness of: cylindrical and bevel gears, crankshafts or camshafts, transmission shafts, worm screws and wheels, bearings, cycloidal drives as well as components such as gear reducers and gearboxes.

Laboratory tests on gears – functional study

Correct geometries mean controlling vibration and acoustics. Appropriate surface treatments ensure system longevity. Correct lubricants ensure enhanced life expectancy for gears. These studies can be performed in the design phase or on functional prototypes. But above all on components that have reached the end of their working life in order to study the operating conditions.
By way of example, we can carry out:

  • Studies on the amount of wear after a period of operation;
  • Evaluation of contact conditions through profilometry and microscopy studies.
  • Failure analysis (SEM/EDX) to evaluate the causes of a breakage.
  • Fractographic examinations using optical and scanning electron microscopy (SEM)

Innovation and gear analysis

If your company has a strong focus on product innovation, we can offer you the following services:

  • Measurement of residual particles (Cleanliness)
  • Measurement of the quantity of residual oil after manufacturing.
  • Advanced study of the geometric quality of construction (3D model – real object)
  • Definition of the calibration of master gears for measuring gearing