Comparison between Internal Grinding Machines and Honing Machines

Honing machines allow users to overcome the weaknesses of internal grinding machines. This page explains how the mechanisms of these two machines differ and why honing machines produce higher quality while also helping lower costs. Please use it when making capital investment decisions and help the Indian manufacturing industry succeed in the global market.

[Comparison Table] Key differences between internal grinding machines and honing machines

Internal grinding machines and honing machines are similar yet have important differences: how their honing stones are applied (contact area), their cutting speed, and their cutting temperature. The table below summarizes their characteristics and differences.

Differences in the mechanisms of these machines that affect the quality of their finishes

Let’s look at the technical differences in the mechanisms of internal grinding machines and honing machines that explains why honing machines produce better quality finishes.

1. Thermal damage (damaged layer)

Internal grinding machines rotate honing stones at high speeds, cutting away material from the points of lines of contact between the stones and the material. They have a high amount of momentary friction heat, which produces several disadvantages. Namely, they are prone to producing damaged layers by causing metal surfaces to burn or lose hardness.

In the case of honing machines, multiple honing stones are used, cutting material away from the entire surface of contact with the material. They cut gently, at low speeds and low pressure, so they produce little cutting heat and can be used to process material without negatively affecting its intrinsic qualities. They are less likely to produce defects, which contributes to higher yields.

2. The limits circularity and cylindricality that can be achieved for deep holes

Internal grinding machines push the honing stones against the material pushing the axis horizontally. One of the disadvantages of this is that the pressure causes the axis to bend, so the deeper the hole, the more likely there will be tapering defects (the hole becoming smaller at its end).

With honing machines, on the other hand, it is more like opening an umbrella within a tube. Pressure is applied uniformly in all directions through the use of the “fixed pressure expansion” method. Because the axis does not bend, this offers the benefits of making it easier to achieve the same level of circularity and cylindricality from the mouth of the hole to its end, even for long cylinders.

3. The presence of oil membrane-retaining cross-hatching

If sliding metal surfaces are polished to a mirror finish, they have difficulty retaining oil, and when there is not enough oil, seizing can occur. One of the unique features of honing machines is that they produce a cross-hatched finish with tiny oil-retaining grooves, so they reduce the likelihood of seizing. This contributes to longer product lives by preventing component friction, even in harsh usage environments.

Mechanism differences that contribute to cost reductions

Internal grinding machines only cut a small surface area at a time, so the larger the area to be processed, the more time they take. Honing machines use surface contact in their processing, so they can process large areas at a time. They help shorten tact time while maintaining precision. Another of their advantages is that they have the potential to bring down costs when used to process deep holes or when used in large-scale mass production lines.

Areas where we recommend switching from internal grinding machines to honing machines

Indian manufacturing is increasingly able to provide the levels of quality needed for electric vehicles (EVs), high-precision components, and exports. There is also a rising need for high quality in internal diameter processing. We’ve summarized the areas that require capital investment in honing machines.

Support for processing of high precision components for electric vehicles (EVs)

EVs have quiet engines, so reducing the gear noise (NVH) of their reducers (e-Axles) is a key to achieving competitiveness. Meeting their high surface roughness and circularity requirements is difficult to accomplish with an internal grinding machine, so honing machines are a solid choice for them. It’s important to review and revise entire processing sequences based on required quality levels and workpiece conditions.

Extending the service lives of hydraulic cylinders and aerospace components

For the hydraulic cylinders used in construction machinery, which is operated in harsh environments, and the components used in aerospace applications, where there is no tolerance for malfunctions, micro-cracks caused by thermal damage are unacceptable. Honing machines, which can ensure a high level of accuracy and durability even for deep holes, without subjecting materials to thermal loads, are an important form of capital investment that directly affect product reliability.

If you suffer from poor yields, realize the limits of your current processing method and make the leap

If you’re struggling with inconsistent dimensions, seizing, or long tact times, these may be the result of your reaching the limits of internal grinding itself. To meet exacting quality requirements, reduce losses from defects, and maximize profit, consider investing in a honing machine that uses surface area contact to process materials without causing thermal damage.

This site presents a selection of honing machines, categorized by business sector, which can allow you to go beyond the limitations of internal grinding and can help free the Indian manufacturing industry from reliance on individual operators. Use it in your comparison and deliberations as you build your own next-generation lines and improve your processing approach.