You ask, we answer.
From customers, inquisitive minds, and friends alike, we receive a wide variety of questions about Superfinishing. Some of the most frequently asked questions will be featured here. Increase your knowledge on this abrasive machining process, brought to you with new exciting facts every week!
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Double Disk Grinding
Why is Double Disk Grinding important? When does it happen during manufacturing?
In situations where both sides of a workpiece must be ground, and those surfaces need to be exactly plane and parralel, Double Disk Grinding becomes imperative. DDG occurs near the end of the manufacturing process, as the stock removal is small and tolerances are precise.
What are Double Disk Grinding
wheels made of?
Depending on the workpiece material, conventional as well as CBN (Cubic Boron Nitride) or diamond wheels can be used in our double-disc grinding machines.
How is Double Disk Grinding more effective than other similar processes?
Double side face grinding allows simultaneous machining of two parallel external surfaces. The workpieces are carried out unclamped in nests of a transport wheel between the two grinding wheels, which allows very fast cycle times to be realized.
Find out more ...What is Plane Parallelism
and why is it important?
Plane parallelism is the property of two opposing flat part surfaces that are parallel to each other. It is necessary for components that are built into a system/assembly.
What are the different types of parts and materials are compatible with Double Disk Grinding?
Materials that can be ground include steel, sintered metal, non-ferrous metal, plastics, ceramics and glass.
What’s the difference between Double Disk Grinding and Fine Grinding?
Each of these machining technologies has its particular strengths. For maximum stock removal as well as output of finished workpieces, double-disk grinding is preferred. For example, within large-scale production, single cams can be ground with a cycle time of fewer than 0.5 seconds with a continuous-feed loading system.
However, for maximum precision and size accuracy, fine grinding is preferred. Hydraulic components, for example, can be finished with an accuracy of ± 0.001 mm.
What stock removal rates can be achieved with Double Disk Grinding?
Two powerful motors achieve stock removal of over 1mm at cycle times well below one second. In just one pass, the workpiece is machined to an average tolerance of +/- 0.003mm.
Superfinishing
When in the machining process does Superfinishing happen? Why does it happen at this phase?
Superfinishing is typically one of the last operations, after rough machining, heat treating, grinding / hard turning.
Since superfinishing surfaces are typically critical bearing or seal surfaces, all of the previous operations are required to get the surface to the condition needed for the final surface finish.
How many different types of grit/stone are there/what do they offer to the process?
There are hundreds, maybe thousands, of different possible stone specifications. Abrasives are typically aluminum oxide or silicon carbide, with some diamond for hard coatings.
Grit sizes vary from 220 to 1500 mesh. Vitrified ceramic bonds are most common and these are available in a variety of hardnesses and treatments. The numerous options make it possible to fine tune a stone specification for a given application.
What is a pneumatic oscillator and what makes it more effective?
The pneumatic oscillator delivers very high frequency (1600-5100 strokes minute), short amplitude (0.35-3mm) oscillation in a robust, mass-balanced design. The linear and fast movement ensures constant stock removal from the workpiece and uniform stone resharpening on the superfinishing stone.
The pneumatic oscillators have a lower mass and smaller dimensions than the mechanically driven oscillators.
What’s the importance of a cross-hatch finish? What benefits are there?
The cross-hatch, plateau finish improves the tribological characteristics of the surfaces by reducing preliminary wear, lowering the coefficient of friction, and providing pathways for lubricant to be distributed across the surface.
What different types of materials can be improved by Superfinishing?
Hardened steels, soft steels, various coatings such as chrome or hard coatings, and nodular iron are the most common materials that can be enhaned by superfinishing, given their widespread use in numerous bearing and power transmission applications.
But any material where sliding or rotational friction is a concern can benefit from the finishes which can be achieved with superfinishing.
What tolerances can be achieved with Superfinishing?
Typical results are:
- Ra < 0.025 [µm]
- Roundness < 0.5 [µm]
- Flatness < 1 [µm]
What is ... Superfinishing?
Look out for our "What is..." YouTube series; a brief introduction to Superfinishing technology.
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What is ... Flat Finishing?
Look out for our "What is..." YouTube series; a brief introduction to Flat Finishing technology.
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Superfinishing Technology
Everything you need to know about the technology for the perfect surface.
