Rochester Magnet

Module Overview

What Is A Magnet?

An object that creates a magnetic field is a magnet, and a magnetic field is characterized as an energy field that attracts ferrous compounds and attracts or repels other magnets.

How Do They Work?


The movement of electrons creates energy, so when a number of electrons are in alignment in terms of their direction, they create sufficient energy to attract other objects with opposite yet similarly aligned electron movements. The directional nature of the movement is responsible for the opposite attractive forces generally called "Poles" and identified as "North" and "South".

What Are They Made of?

A list of magnet materials is provided below - each has a unique set of characteristics and applications.

Magnetic Material Comparison Chart

Material  Residual Flux Density Br (Gauss)   Maximum Coercive Force Hc (Oersteds)  Energy Product BHmax (MGOe) Slope of Load Line at BHmax Curie Point (°C) Maximum Practical Operating Temp. (°C / °F) Temp. Coefficient (% Loss / °C) Relative Density (Lbs. / Cubic Inch)
Sintered Alnico II                 7,100                        560 1.5 12.3 840 540 / 1000 0.015 0.247
Cast Alnico V              12,800                        640 5.5 18 890 540 / 1000 0.013 0.264
Sintered Alnico V              10,900                        620 3.95 18.4 860 540 / 1000 0.007 0.253
Cast Alnico VIII                8,200                     1,650 5.3 5 870 540 / 1000 0.013 0.265
Sintered Alnico VIII                7,400                     1,500 4 5 840 540 / 1000 0.007 0.253
SmCo 18                8,500                    8,000 18 1 700 260 / 500 .030 - .045 0.3
SmCo 22                9,500                    8,600 22 1 825 260 / 500 .015 - .030 0.3
SmCo 26              10,500                    9,200 26 1 825 350 / 660 .015 - .030 0.3
NdFeB 27              10,800                  10,000 27 1 300 80 / 176 0.12 0.267
NdFeB 30H               11,600                   11,000 30 1 300 120 / 248 0.12 0.267
NdFeB 35              12,200                   11,800 35 1 300 80 / 176 0.13 0.267
Ceramic I                2,300                     1,860 1 1.2 460 400 / 750 0.129 0.167
Ceramic V                3,800                    2,400 3.4 1.1 460 400 / 750 0.19 0.18
Ceramic VIII                3,850                    2,950 3.5 1 460 400 / 750 0.19 0.18
Flexible Regular                 1,600                     1,370 0.6 1.2 * 70 / 160 0.19 0.133
Flexible High Force                2,200                     1,900 1.1 1.2 * 70 / 160 0.19 0.14
*  Standard Flexible Magnets contain bonding agents that may cause the loss of magnetization at temperatures above 1600 F (700 C)
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