{"id":1146,"date":"2021-08-05T14:48:00","date_gmt":"2021-08-05T14:48:00","guid":{"rendered":"https:\/\/www.first4magnets.com\/us\/blog\/?p=1146"},"modified":"2025-03-24T11:18:01","modified_gmt":"2025-03-24T11:18:01","slug":"how-is-the-strength-of-a-magnet-measured","status":"publish","type":"post","link":"https:\/\/www.first4magnets.com\/us\/blog\/how-is-the-strength-of-a-magnet-measured\/","title":{"rendered":"How Is The Strength Of A Magnet Measured?"},"content":{"rendered":"\n

When considering the \u2018strength<\/a>\u2019 of a magnet there are several key measurements that all contribute to a magnet\u2019s strength in different ways, which can be a little confusing.<\/p>\n\n\n\n

Also, when trying to determine or measure the strength of a magnet the answer will be dependent on what is meant by strength be it either the pulling force or magnetic field strength, which are both often referred to as strength. <\/p>\n\n\n\n

So below we will describe each attribute that contributes to the performance of a magnet and in turn answer the question how is the strength of a magnet<\/a> measured?<\/p>\n\n\n\n

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Maximum Energy Product<\/strong> <\/p>\n\n\n\n

The first contributing attribute is a magnets maximum energy\nproduct, this is measured in Mega Gauss Oersteds (MGOe). <\/p>\n\n\n\n

This is the primary indicator of a magnet\u2019s \u2018strength\u2019 as\nusually the higher the maximum energy product value, the greater the magnetic\nfield generated by the magnet. <\/p>\n\n\n\n

To calculate the maximum energy product, take a magnet\u2019s remanence (Br) and multiply it by its coercivity (Hc). <\/p>\n<\/div>\n\n\n\n

\n

Remanence<\/strong><\/p>\n\n\n\n

The remanence is described as the magnetism that is left in\nthe magnet after the removal of external magnetic force applied to magnetise it,\nthis is measured in Gauss. <\/p>\n\n\n\n

When a material has been magnetised, it will have remanence, as the magnetism has previously been induced by an external magnetic field.<\/p>\n\n\n\n

The remanence value of a magnet is the flux density held by the magnet whilst in a closed circuit.<\/p>\n<\/div>\n<\/div>\n\n\n\n

Coercivity<\/strong><\/p>\n\n\n\n

The coercivity of a magnet is the energy which is required to reduce the magnetisation of a magnetised object to zero, which had previously been magnetised to the point of saturation. <\/p>\n\n\n\n

Essentially, it measures a magnetic materials resistance to demagnetisation\nand is measured in Oersteds. <\/p>\n\n\n\n

Each factor can only be measured with a hysteresis graph testing machine which plots a second quadrant hysteresis curve. <\/p>\n\n\n\n

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Open Circuit Flux Density<\/strong><\/p>\n\n\n\n

The intensity of a magnetic field, measured in Gauss or\nTeslas (10,000 Gauss = 1 Tesla), is also a very common measurement of a magnets\nstrength as it is the representation of the density of a magnetic field\nproduced by a magnet, known as flux density.<\/p>\n\n\n\n

A magnetic field can be visualised as magnetic lines passing\nthrough a magnet along the direction of magnetism, the field strength relates\nto the density of the lines over a given area and the total number of lines is\nthe magnetic flux density. <\/p>\n\n\n\n

The remanence value of a magnet is the flux density held by the magnet whilst in a closed circuit, but after being removed from the testing machine it is no longer in a closed circuit and is in an open circuit. The magnetism will fall instantly to a lower level which will be dependant on the ratio between the surface area and its relative magnetic length. <\/p>\n\n\n\n

For example, magnets with small poles and long lengths have a much higher open circuit flux densities in comparison to magnets with large poles and small magnetic lengths. <\/p>\n<\/div>\n\n\n\n

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.<\/p>\n\n\n\n

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.<\/p>\n\n\n\n

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Pull Strength<\/strong><\/p>\n\n\n\n

Neodymium magnets<\/a> are very commonly used, and manufacturers and suppliers will provide strength for each of their magnets to show how much weight a magnet can hold.<\/p>\n\n\n\n

The pull strength is the highest possible holding power of a\nmagnet, measured in kilograms. This is the force required to prise the magnet\nfrom a flat steel surface when they are in direct surface-to-surface to contact.\n <\/p>\n\n\n\n

The grade of the metal, surface condition and angle of pull\nwill all have an impact on the pull strength of a magnet. <\/p>\n\n\n\n

Pull Gap Curve<\/strong><\/p>\n\n\n\n

A pull-gap curve plots the\npulling power of a magnet in direct contact with a thick and flat piece of\nsteel and then through a steadily increasing range of air gaps. All magnets can\nbe tested over a variety of air gaps using a pull-gap testing machine.  <\/p>\n<\/div>\n<\/div>\n\n\n\n

So, when it comes to selecting a magnet the key things to look out for are the maximum energy product value of a magnet, the open circuit or surface gauss value and the maximum pull strength. These attributes give you the opportunity to compare individual magnets. <\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

When considering the \u2018strength\u2019 of a magnet there are several key measurements that all contribute to a magnet\u2019s strength in […]<\/p>\n","protected":false},"author":4,"featured_media":4022,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"footnotes":""},"categories":[5,19],"tags":[156,157,158,159],"class_list":["post-1146","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-frequently-asked-questions","category-magnet-information","tag-field-strength","tag-magnet-strength","tag-strong-magnet","tag-strong-magnets-2"],"_links":{"self":[{"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/posts\/1146","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/comments?post=1146"}],"version-history":[{"count":2,"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/posts\/1146\/revisions"}],"predecessor-version":[{"id":5026,"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/posts\/1146\/revisions\/5026"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/media\/4022"}],"wp:attachment":[{"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/media?parent=1146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/categories?post=1146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.first4magnets.com\/us\/blog\/wp-json\/wp\/v2\/tags?post=1146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}