External cylindrical grinding machine

External cylindrical grinding machines for industrial production

How an external cylindrical grinding machine works

An external cylindrical grinding machine is a machine tool that has been specially developed for the precision grinding of cylindrical outer surfaces of workpieces. External cylindrical grinding is a machining process and is used in particular for the finishing of rotationally symmetrical workpieces. The machining process is carried out with a rotating grinding wheel that turns at high speed and removes the material by micro-chipping.

Structure of an external cylindrical grinding machine

An external cylindrical grinding machine consists of several assemblies that work together precisely. The machine frame forms the stable basic structure. The grinding headstock with the rotating grinding wheel and the workpiece headstock, which holds and turns the component to be machined, are mounted on it. A tailstock provides additional support for the workpiece. The longitudinal and cross slide guides enable precise movement of the sanding unit. Modern machines also have a CNC control system, integrated measuring systems and a coolant system, which reduces the thermal load and improves the sanding result.

Other types of cylindrical grinding machines

At maschinenauswahl.de, we differentiate between the following types of cylindrical grinding machines:

The following search terms are often used for external cylindrical grinding machines: CNC external cylindrical grinding machine, centreless external cylindrical grinding machine, external cylindrical grinding machine structure, conventional external cylindrical grinding machine, CNC cylindrical grinding machine

External cylindrical grinding machine external cylindrical grinding machine

Production with the external cylindrical grinding machine

CNC grinding begins with the workpiece being fixed between a centre bearing or in a chuck. The workpiece rotates evenly around its own axis during machining. Parallel to this, the grinding wheel moves axially or radially over the surface to be machined. The surface is removed step by step until the desired dimensional accuracy, surface quality and roundness is achieved. The grinding discs are usually made of hard materials such as corundum or CBN (cubic boron nitride), which can also machine hard materials precisely.

Different methods for external cylindrical grinding

There are different methods within external cylindrical grinding, including longitudinal grinding, in which the grinding wheel and workpiece move axially in relation to each other, and plunge-cut or pendulum grinding, in which the grinding wheel oscillates within a defined range. Modern machines are CNC-controlled and enable complex machining cycles with high repeat accuracy. They often have integrated measuring systems for automatic quality control during the grinding process.

Application in industrial metalworking

External cylindrical grinding machines are used wherever maximum precision is required for cylindrical components. In the automotive industry, they are used to machine camshafts, crankshafts or piston rods. Mechanical engineering uses them for spindles, shafts or bearing journals. In the aerospace industry, they are used in the production of engine parts and drive shafts. Other fields of application include medical technology, toolmaking and energy technology.

Typical workpieces are

Engine shafts
crankshafts
camshafts
guide rods
Hydraulic cylinders
Spindles
Threaded spindles
pins
Bearing journals
Axles

These workpieces require the highest concentricity and surface quality, which can only be achieved by external cylindrical grinding.

Accuracy in external cylindrical grinding

Dimensional accuracy (IT classes)

Tolerance classes in the IT5 to IT6 range are common for external cylindrical grinding. With particularly precise machines and under controlled conditions, tolerances up to IT4 can also be achieved. This means that dimensional deviations in the range of 2-10 micrometres (μm) are possible.

Roundness and cylindricity

Roundness deviations can be reduced to less than 1 μm with high-quality CNC external cylindrical grinding machines. Cylindricity errors also often remain below 2-3 μm, provided the machine is precisely aligned and thermally stable.

Surface quality (roughness)

The achievable roughness (Ra) depends heavily on the abrasive used and the process control:

Standard Ra values: 0.2 - 0.4 µm
Ultra-fine machining: up to 0.05 µm with CBN or diamond grinding

Grinding brass or machining brass surfaces

External cylindrical grinding of brass requires special attention, as this material has specific mechanical and thermal properties that influence the grinding process. Brass is a copper-zinc alloy that is relatively soft, tough and thermally conductive - which brings both advantages and challenges.

Material behaviour and chip formation

Brass forms short but tough chips during grinding, which tend to embed themselves in the grinding wheel (lubricating effect). This leads to clogging and can significantly impair the grinding performance and surface quality. Lead-free brass alloys are particularly affected by this. Regular grinding wheel cleaning and dressing is therefore necessary.

Grinding wheel selection

Medium-hard to hard grinding wheels with an open structure are suitable for brass in order to minimise clogging. Abrasives such as corundum (aluminium oxide) or silicon carbide are commonly used. A low bond density helps to keep the grinding wheel surface free.

Cooling and lubrication

Although brass has good thermal conductivity, inadequate cooling can lead to thermal hardening or lubrication. An effective supply of cooling lubricant is therefore crucial. Emulsions with high pressure and good flushing properties are advantageous.

Machining parameters

Due to the softness of brass, the contact pressure should be reduced in order to avoid plastic deformation or scoring. At the same time, high grinding speeds are possible as brass offers little abrasion resistance.

Surface quality

Brass allows for very fine surfaces during external cylindrical grinding - Ra values of less than 0.2 µm are realistic. This is a significant advantage for decorative components.

Tools for an external cylindrical grinding machine

Grinding discs are primarily used in external cylindrical grinding machines. These consist of various abrasives such as aluminium oxide (Al₂O₃), silicon carbide, cubic boron nitride (CBN) or diamond. Typical tools are

Aluminium oxide grinding wheels
CBN grinding discs
Diamond grinding discs
Segmented grinding discs
Profiled grinding discs
Cup wheels
Grinding discs with ceramic bond
Resin-bonded grinding discs
Rough grinding discs
Fine grinding discs

The choice depends on the material, precision and processing objective.

Accessories and operating materials for an external cylindrical grinding machine

You need the following accessories and operating materials to operate an external cylindrical grinding machine: Coolant systems that prevent overheating and ensure dimensional accuracy. Grinding wheel dressers ensure that the shape of the grinding wheel is maintained. Workpiece clamping devices such as chucks or centres enable secure fixing. Other operating equipment includes grinding wheels, measuring equipment for quality control, filter systems for the cooling lubricant and extraction systems to protect against grinding dust. Automated loading systems can also be integrated as an option to optimise the production process.

Leading manufacturers of external cylindrical grinding machines

In our manufacturers directory, you will find companies that produce external cylindrical grinding machines for metalworking.

The following terms are frequently searched for: Bahmüller external cylindrical grinding machine, dama external cylindrical grinding machine, Danobat external cylindrical grinding machine, DVS external cylindrical grinding machine, EMAG externalcylindrical grinding machine, Geibel external cylindrical grinding machine, GP external cylindrical grinding machines, Jainnher external cylindrical grinding machine, Junker external cylindrical grinding machine, Kaast cylindrical grinding machine, Kellenberger external cylindrical grinding machine, Knuth external cylindrical grinding machine, Lizzini external cylindrical grinding machine, Okamoto external cylindrical grinding machine, Okuma external cylindrical grinding machine, Palmary external cylindrical grinding machine, Rettificatrici Ghiringhelli external cylindrical grinding machine, Rollomatic cylindrical grinding machine, Saeilo external cylindrical grinding machine, Schaudt external cylindrical grinding machine, Studer external cylindrical grinding machine, Tacchella external cylindrical grinding machine, Toyodacylindrical grinding machine, Tschudin external cylindrical grinding machine, Ulmer Werkzeug-Schleiftechnik external cylindrical grinding machine, United Grinding Group external cylindrical grinding machine, Wagner external cylindrical grinding machine, Weiss external cylindrical grinding machine, WEMA external cylindrical grinding machine, Ziersch external cylindrical grinding machine

Selecting the right external cylindrical grinding machine

If you want to buy an external cylindrical grinding machine, there are several important features and specifications to consider.

One key feature is the grinding diameter range, which determines the maximum workpiece size that can be processed.
Equally important is the centre width and height to take into account the dimensions of the workpiece.
The rigidity of the machine bed and the precision of the guides have a significant influence on the machining quality.
The choice between manual and CNC-controlled machines depends on the degree of automation and the production volume.
Other relevant specifications include the type and bond of the grinding wheels, the feed rate, the speed control of the workpiece and grinding spindle as well as existing measuring and correction systems.
Automated clamping systems and workpiece changers are advantageous for series production.
A user-friendly user interface, energy efficiency and ease of servicing round off the requirements profile.

Find the external cylindrical grinding machine that suits your production requirements now at maschinenauswahl.de.

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All machines from the category External cylindrical grinding machine