Star Trace (P) Ltd.

Quality and customers’ oriented company engaged in manufacturing, exporting and supplying a comprehensive range of contemporary Rare Earth Magnets, which are offered at customers’ leading prices to satisfy the customers across Asia and other parts of the world. An assortment of Rare Earth Circular Magnets is designed and manufactured by us following able guidelines of those personnel who have sound educational background and expertise in this sector. Application of high quality raw material in Rare Earth Circular Magnets manufacturing increase reliability and performance of products.

Generally, the elements are melted together and milled into a power that is dry-pressed to shape in the presence of a magnetic field. The material is then sintered, aged, ground to dimension, magnetize and tested. These are called "Rare Earth" Magnets because the elements of neodymulum and samarlum are classified in the lanthanides section of the Periodic Table of the Elements.

Neodymium Magnets (Nd-Fe-B) are composed using Neodymium, Iron, Boron and few transition metals. Samarium Cobalt magnets (SmCo) are composed from samarium, cobalt and iron. These Earth Magnets are extremely strong for their shapes as rings, blocks and discs.

Neodymium

Attributes of Neodymium

• Very high resistance to demagnetization


• High energy for size


• Good in ambient temperature


• High priced


• Material is corrosive and should be coated for long term maximum energy out put


• Low working temperature for heat applications

Application of Neodymium

Neodymium is applied in Magnetic Separator, Linear Actuators, Microphone Assemblies, Servo Motors, DC motors (automotive starters), computer rigid disc drives, hammer bank printers, and speakers.

Samarium

Attributes of Samarium

• High resistance to demagnetization


• High energy (magnetic strength is strong for its size)


• Good temperature stability


• Expensive material (cobalt is market price sensitive)

Applications of Samarium

• Computer disc drives


• Sensors


• Traveling wave tubes


• Linear actuators


• Satellite systems


• Motors where temporary stability is vital

Rare Earth Tolerances
For as pressed material, tolerance on the thickness (direction of magnetization) is +/-.127mm. Other Dimensions are +/-2.5% or +/-.254mm, which is greater.
According to Magnet Materials Producers Association (MMPA) standards, visual imperfections such as hairline cracks, porosity and minor chips are commonly found in sintered metallic magnets. A chipped edge is considered acceptable if less than 10% of the surface is missing. Cracks are acceptable as long as they do not extend across more then 50% of pole surface.

Rare Earth Magnetizing and Handling

Rare Earth Magnets offered by Star Trace are very brittle and magnetically strong. Therefore, it is crucial to handle these magnets with extreme care to avoid personal injury and damage to the magnets. Fingers can be severely pinched between attracting magnets. Magnets can be chip if allowed to “Jump at” an attracting object. It is highly recommended that when constructing Rare Earth Magnetic assemblies, they can be magnetized after assembly.

Rare Earth Machining

Since Rare Earth Magnet material is highly prone to chipping and cracking, it does not lend itself to conventional machining methods. It can, however, be abrasively ground, but only with the use of liberal amounts of coolant. The coolant minimizes heat fracturing and the risk of fires caused by oxidized grinding dust.

Typical magnetic and physical properties of Rare Earth Magnet material