In precision mechanics shops, there are many processes that are put in place: after discussing CNC turning and mechanical milling, in this article we will look at what is meant by precision grinding.
It may be useful to begin by taking up the definition of 'grinding' provided by the Treccani encyclopedia: "The action and operation of grinding, the fact of being ground, and the effect thereof. It concurs with rectification, in comparison with which rectification is the preferred, and often exclusive, form in bureaucratic use, in technology, especially mechanical. [...] Rectification is, moreover, the only form used to indicate the fact of rectifying, that is, of correcting."
In the next few lines we will go into the heart of the matter, delving into what it is, how it works and what this processing is for.
What is Precision Mechanical Grinding and what is it used for?
Precision mechanical grinding refers to a finishing procedure, performed by means of a machine tool that goes by the name of grinding machine, used to remove excess metal from any mechanical component, or material, in order to return it to its optimum shape or surface state.
Typically, grinding follows degreasing: first, and in the shortest possible time, most of the residue is removed, and only later is the punctual correction of the remaining imperfections carried out. The final result is a finely processed product marked by a high degree of precision.
Although it is necessary in a great many areas and finds many areas of application, precision mechanical grinding is used for the manufacture of:
- Precision engineering products such as surfaces plates, dressing plates, cylinders and control blocks and control rulers, Mounting and Parallel Boxes
- Aerospace parts
- Machine tool gears, bearings and guides
- Drive shafts
- Molds and measuring tools
How does Precision Grinding work?
Precision mechanical grinding operations are achieved by abrasion exerted by a fine-grained, extremely hard grinding wheel. Rotating at very high speeds, the grinding wheel removes material from the workpiece with the goal of achieving measurements, diameters, dimensions and roughness on the order of a thousandth of a millimeter.
The process ends when the component reaches the optimum design state.
The different types of Grinding
The types of precision mechanical grinding differ depending on the machinery that performs them, the surfaces machined, and the direction along which the grinding wheel moves relative to the workpiece.
In particular, we recognize:
- Cylindrical grinding: used to grind surfaces with a cylindrical, conical or shaped shape. It is performed on both internal and external surfaces, and the relative motion of the grinding wheel is usually latitudinal and longitudinal
- Plane grinding: is used to make flat surfaces with high surface finishes. Depending on the position of the grinding wheel, there is either tangential grinding (involves tangent contact between the grinding wheel and the machined surface) or face grinding (one face of the grinding wheel lies on the work surface)
- Plunge grinding: similar to cylindrical grinding, it is chosen for material removal operations on conical and cylindrical parts. Plunge grinding takes place with the axis of rotation placed parallel to the workpiece, and the motion of the grinding wheel is, again, either longitudinal or latitudinal
- Centerless grinding: centerless grinding is used for pointwise machining of small cylindrical parts and variable geometry revolution parts
- Electrochemical grinding: this is the most unique type of grinding: in this case, the removal of excess material is not done by abrasion of the grinding wheel by electrolytic effect
Obviously, depending on the type of grinding to be performed, the model of grinding machine chosen changes: we have the round, centerless and tangential grinding machine, in which the only common element is the presence of the spindle where the grinding wheel is placed.
The Numerically Controlled Grinding Machine
As discussed extensively in the dedicated article, technological developments in recent decades have made work in precision machine shops more efficient by introducing numerically controlled machinery.
The CNC grinding machine works in a nearly automated manner thanks to the computerized brain that controls it: the operator, using special software, initiates the removal process, supervising the process at every stage.
In this way, the margin of error is minimized and extreme precision in quality, flexibility and maximum speed of execution are guaranteed.
Bonanomi and Precision Mechanical Grinding for Third Parties
Bonanomi Precision Machine Shop offers precision mechanical grinding service for third parties on any commissioned mechanical part. Using advanced machinery and an experienced team, it provides a very high degree of finish on a wide range of materials: from stainless steel to noble metals, G25 cast iron, not to mention aluminum, brass, plastic, wood and some hard stones.