What is an indexable insert?

What is an indexable insert?

An indexable insert is a tool in which a pre-processed polygonal insert with several cutting edges is clamped on the cutter body using a mechanical clamping method. When a cutting edge becomes dull during use, just loosen the clamping of the blade and then index or replace the blade so that the new cutting edge enters the working position and can be used again after clamping.

Indexable tools have two characteristics compared with welded tools and integral tools：

1) The insert installed on the cutter body has at least two pre-processed cutting edges for use. (Some special blades cannot be indexed and can only be replaced, such as ball-head blades)

2) The position of the cutting edge on the cutter body remains unchanged after the insert is indexed, and it has the same geometric parameters.

Indexable inserts have the following characteristics compared with welded tools:

1) The insert becomes an independent functional component, and its cutting performance is expanded and improved;

2) The mechanical clamping type avoids the influence and restrictions of the welding process, and is more conducive to selecting blades of various materials according to the processing object, and fully exerts its cutting performance, thereby improving cutting efficiency;

3) The spatial position of the cutting edge is fixed relative to the tool body, which saves the auxiliary time required for tool changing, tool setting, etc., and improves the utilization rate of the machine tool.

4) Because the indexable tool has high cutting efficiency and less auxiliary time, the work efficiency is improved, and the cutter body of the indexable tool can be reused, saving steel and manufacturing costs, so it is economical. The development of indexable cutting tools has greatly promoted the advancement of tool technology. At the same time, the specialized and standardized production of indexable cutter bodies has promoted the development of cutter body manufacturing processes.

 There are many types of blade materials, which can be divided into the following 6 types:

1) Carbide-blade

2) Coated carbide-blade

3) Cermet-blade

4) Pure ceramic-blade

5) CBN cubic boron nitride-insert (more turning)

6) PCD diamond-blade

Different types of indexable insert materials determine the processed materials and prices.

For example, cermets, pure ceramics, CBN, and PCD are relatively expensive.

1) Cermet: brittle and hard, with good wear resistance, mostly used in finishing;

2) Pure ceramic: HRC hard material with hardness between 45º and 55º;

3) PCD: mostly used for mirror processing of aluminum alloys;

4) CBN: hardened material with a hardness above 55 ºHRC. It is common in turning and rarely used in milling.

Due to the hard and brittle characteristics of the material, materials with low PCBN content are prone to chipping during the grinding process. Chipping shortens tool life because it negatively affects the cut and results in higher edge loading. Therefore, in the process of manufacturing indexable inserts, the protective chamfer must be ground after grinding the periphery.

PCBN indexable inserts are usually ground using vitrified bond diamond grinding wheels. Ceramic diamond peripheral grinding wheels have the following advantages. 1. Better thermal stability. The ceramic bonded peripheral grinding wheel has good heat resistance and small thermal expansion, making it less likely to heat up and become clogged during grinding. 2. Better surface retention. The ceramic bonded peripheral grinding wheel has high strength and good grinding effect. It can maintain the shape of the grinding wheel well, is not easy to deform, and makes it easier to control the processing accuracy. 3. Longer life. Due to the strong thermal stability and high surface retention performance of the ceramic bonded peripheral grinding wheel, its grinding efficiency is higher and the cutting edge is sharper. The service life of the grinding wheel will also be longer than that of the resin bonded peripheral grinding wheel. longer.

Application areas:

Various indexable turning, milling, drilling, cutting inserts, welding inserts, machine clamp inserts, etc.

Processing objects:

Carbide, PCD, PCBN, ceramics, cermet

How to choose diamond grinding wheel and CBN grinding wheel for processing indexable inserts?

Typical grinding steps: