| The precision surface grinder is a machine tool | | | | diamond at the top of the range, through cubic |
| that is capable of working to a fine tolerance of | | | | boron nitride and silicon carbide to aluminium oxide. |
| plus or minus 0.002 millimetres, or to around plus | | | | The most commonly used is aluminium oxide |
| or minus one ten thousandth part of an inch in | | | | because of its efficiency and it relatively low cost |
| the old imperial measurement scale. This is an | | | | of replacement. Because diamond and cubic boron |
| extremely high degree of precision and naturally | | | | nitride are very expensive to produce, the wheels |
| requires a skilled operator to achieve it. Of course, | | | | normally have a core comprised of a hard, but |
| much depends on the material being worked with, | | | | less expensive material with only the outer |
| as well as the type of grinding wheel being used. | | | | surface of the wheel being either diamond or |
| The surface grinder usually has a table where the | | | | cubic boron nitride. |
| work piece is attached with the grinding wheel | | | | The extremely high degree of precision achievable |
| positioned above it. The work piece requiring | | | | with a surface grinder depends largely on the |
| grinding can be traversed in two horizontal | | | | condition of the grinding wheel. For this reason |
| directions, either across the face of the grinding | | | | dressers are used to dress the grinding wheels |
| wheel, or longitudinally. By using the two direction | | | | back into peak condition. It is also necessary to |
| operating wheels in tandem, the work piece can | | | | use suitable coolant lubrication on the work piece |
| be positioned precisely where it is needed. | | | | while the grinding operation is in progress. This has |
| Grinding of a metallic surface requires the work | | | | a dual purpose: the lubricate the grinded surface |
| piece to be firmly attached to the table. This is | | | | and keep temperatures down, as well as the |
| usually achieved by means of a magnetic chuck | | | | continual removal of swarf, or the unwanted |
| that can hold a piece of metal firmly in position | | | | material that has been ground away. |
| while it is being grinded. The magnetic chuck can | | | | The precision surface grinder can achieve |
| be either electromagnetic or a permanent magnet | | | | amazingly high degrees of machined accuracy in |
| type. Naturally, this type of chuck can only work | | | | the right hands. It can usually achieve greater |
| with metals that are attracted to a magnet, | | | | machined accuracy than other commonly used |
| which includes all types of steel, the most | | | | types of machine tool, such as a milling machine |
| commonly ground metal. | | | | or lathe. With the use of specialised computer |
| The material used for the surface face of the | | | | software, the level of precision becomes almost |
| grinding wheel is important. These range from | | | | impossible, and in high demand in today's world. |