Ferrites are a type of ceramic compound composed mainly of iron oxide (Fe₂O₃) combined with one or more additional metallic elements. They are both electrically nonconductive as well as being ferrimagnetic as they can be magnetized or attracted to magnets.
There are two main types of ferrite based on their magnetic coercivity, i.e. their resistance to being demagnetized. Hard ferrites have high coercivity and are thus difficult to demagnetize. Soft ferrites have a low coercivity and are used in the electronics industry to make ferrite cores for inductors and transformers, and as microwave components. These cores usually contain nickel, zinc, or manganese compounds.
Manufacturers produce so many grades of ferrite of different composition and properties that we generally prefer our customers to stipulate the grade which suits their particular application best. In most cases the correct material is sent to us for machining on a free-issue basis.
Ferrite is the most brittle material that we machine and is also the most susceptible to thermal shock. As a result, we have developed special machining and handling techniques when working on ferrite components for our customers. We are frequently asked to adjust the length of the legs or center spigot of standard ‘I’ or ‘E’ cores or to machine the ‘as fired’ surfaces to ensure that they mate accurately with each other. Apart from this our operators are highly skilled in producing fragile, complex and at times, extremely small components in this material from either solid blocks or pre-pressed blanks.