Grinding is done for a variety of different reasons. It can be completed to develop a flat and even surface, such as in rotary grinding and Blanchard grinding, or it can be done to create threads or to create internal and external dimensions to high degrees of tolerance. There are additional types of processes, such as jig grinding, that create very exacting tolerances on simple to complex shapes.
Since jig grinding is used to create precision holes in components as well as surfaces that have tolerances of 0.0001 inch or less, they are some of the most precise grinders available. Many typical machine shops do not have specific jig grinding equipment and, while they can make the components, they cannot provide to tight tolerances required for a variety of different industries, applications and components.
The Equipment
All jig grinding is done on a precision grinding machine known as a jig grinder. It is smaller in width than many of the CNC grinding machines and is often used to create very specific dies for tooling and use in a variety of different applications.
The larger machines used for jig grinding allow complex patterns to be created on a single machine. This is possible through the use of different tools, as well as different grinding bits to achieve the different bores, shapes and grinding requirements to create the specific shape.
Another important consideration in jig grinding is the speed that can be obtained through the spindle that rotates the grinding tool. There are some machines that have a fixed speed, which are commonly used for standard types of alloys. For specialized applications or for high levels of precision there are high-speed machines that are rated for up to 175,000 rpm.
Jig Boring and Grinding
Jig boring is the specific task used mostly in the development of dies or of tools and components where there will be a need for extremely precise positioning of holes that are of a very specific size. For example, in a die that uses a hole and pin system, the position of the holes will be completed through the use of a jig bore process.
With jig grinding, bores can also be produced, but there is a greater ability to create different shapes rather than a simple hole. Both options provide a very smooth interior surface that is accurate and repeatable time and time again.
