Spindle
Accessories
- Abrade hard materials
- Improve surface finish
- Tighten the tolerance on cylindrical or flat surfaces by removing a small amount of material
- Resharpening cutting tools
- Surface grinding of mold sections
- Surface grinding of work fixtures
- Internal diameter and outer diameter grinding of valve bodies, and many other useful applications.
Grinding process
For material removal, the method used in grinding is called abrasion. In other words, in grinding, an abrasive material rubs against the metal part and clears or removes tiny pieces of material. The process implies that instead of cutting like a lathe bit, the material is slowly and steadily worn away. This is because compared to the material being ground, the abrasive is harder. The grinding wheel actually acts like many hundreds of very small lathe bit, each cutting off some metal. The abrasive must be strong enough to bear any kind of forces acting upon it while grinding. Usually some sort of impact shock occurs when the abrasive comes in contact with the material. Grinding abrades material in a way similar to sanding. The grinding operation is performed on a several machines like the lathe and the mill, with the appropriate add-on accessories, the most important of which is the spindle.
Why grinding is necessary?
Grinding is necessary for the following reasons:
- The material is too hard to be machined economically.
- If the surface is adequately supported, grinding can produce flatness
tolerances of less than ±0.0001 in. (±0.0025 mm) on a 5 x 5
in. (127 x 127 mm) steel surface.
- Machining removes excessive material.
- Grinding should be used when size tolerance specifications are beyond
the capability of turning.
- It is also applied if the requirements of surface finish is too tight for hard turning.
Types of grinding
Grinding can be of various types, like as follows:
- Surface grinding
- Centered grinding
- Centerless grinding
- Contour grinding
Surface grinding: This is perhaps the most fundamental of operations. Surface grinding is the process of providing precision ground surfaces either to a critical size or for the surface finish. In other words, it accurately processes or grounds a surface. Parts require surface grinding for various reasons like:
- Produce a flat surface.
- For specifying accurate tolerance thickness.
- A very smooth surface roughness is required.
- For sharpening of cutting tool.
Centered grinding: In this type of grinding, the grinding is performed at the center. There are two types of centered grinding-OD grinding and ID grinding. In Outside Diameter (OD) grinding , the work piece has center drilled ends, accommodating center points and surface is removed by rotating the grinder's face plate. With OD grinding the work piece and the grinding wheel moves or rotates in clockwise directions. Inside Diameter (ID) grinding is performed on tubular parts that are generally held in a chuck or collet. The grinding wheel turns at very high speed to maintain the proper surface speed but it moves anticlockwise.
Contour grinding: In case of contour grinding, the chopping function is used to grind the side face of a workpiece.
