{"id":3426,"date":"2026-09-28T23:53:29","date_gmt":"2026-09-28T15:53:29","guid":{"rendered":"http:\/\/www.bathroomshowerhose.com\/blog\/?p=3426"},"modified":"2026-09-28T23:53:29","modified_gmt":"2026-09-28T15:53:29","slug":"are-constant-force-springs-affected-by-magnetic-fields-457a-9918e8","status":"publish","type":"post","link":"http:\/\/www.bathroomshowerhose.com\/blog\/2026\/09\/28\/are-constant-force-springs-affected-by-magnetic-fields-457a-9918e8\/","title":{"rendered":"Are constant force springs affected by magnetic fields?"},"content":{"rendered":"

Hey everyone, thanks for stopping by my corner of the internet. I\u2019m Alex, and I run a small constant force spring supply business\u2014for the last 8 years, I\u2019ve been helping all kinds of folks get the right springs for their projects, whether it\u2019s medical devices, automotive parts, or even big industrial equipment. The other day, a customer slid into my DMs asking a question that\u2019s actually way more common than you\u2019d think: \u201cAre constant force springs affected by magnetic fields?\u201d It\u2019s not the first time I\u2019ve gotten this, and honestly? I get why it\u2019s a big deal. If you\u2019re working on a machine that\u2019s near magnets or in a magnetic field, you can\u2019t afford parts that act wonky. Let\u2019s break this down, no fancy jargon, just what I\u2019ve learned from actual customers and testing I\u2019ve done in my workshop. Constant Force Spring<\/a><\/p>\n

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First, let\u2019s make sure we\u2019re on the same page about what a constant force spring is, because if you\u2019re here, you probably already know, but bear with me. These aren\u2019t your regular coil springs that get stiffer or looser as you stretch or compress them. A constant force spring is basically a long strip of flat metal wound tight on a reel. When you pull on the free end, it unwinds, and the tension from the way it\u2019s formed gives you the same amount of force every inch of the way. They\u2019re super popular for things like window shades, retractable tool cords, and even drawer sliders because that consistent force is exactly what you need.<\/p>\n

Now, back to the magnetic field question. Let\u2019s start with the basics: metals and magnets. Not all metals are magnetic, right? You\u2019ve got your ferrous metals\u2014iron, steel, most stainless steels that have iron in them\u2014those get attracted to magnets. Then you\u2019ve got non-ferrous stuff: aluminum, copper, brass, some types of stainless steel that don\u2019t have much iron. So right off the bat, the material your constant force spring is made of is the first big factor here. That\u2019s why I always ask customers to tell me their working environment before I recommend a spring.<\/p>\n

Let\u2019s get into the science, but keep it real. Magnetic fields exert force on moving charged particles, right? For a spring that\u2019s not moving, the electrons in the metal are just zapping around like normal, no net movement, so a static magnetic field (that\u2019s the kind that doesn\u2019t change over time, like a permanent magnet) won\u2019t push or pull on a stationary constant force spring. Wait, but what if the spring is moving? Like, if it\u2019s unwinding or rewinding, the metal\u2019s atoms are shifting a little as the spring bends. Does that interact with a magnetic field? From what I\u2019ve tested and what the engineering data shows, unless the magnetic field is super strong\u2014like, way stronger than what you\u2019d find in most consumer or even industrial setups\u2014you won\u2019t notice any difference in the spring\u2019s constant force. The small movement of the spring\u2019s molecules doesn\u2019t create enough force against a normal magnetic field to change how it works.<\/p>\n

But here\u2019s the catch: alternating magnetic fields. Those are the ones that change direction, like from a motor or an MRI machine. If you have a spring moving in an alternating magnetic field, you get something called eddy currents. That\u2019s when the magnetic field induces tiny electrical currents in the metal of the spring. Those eddy currents create their own little magnetic fields, which actually can slow the spring down or mess with its tension a tiny bit. But again, this only happens if the field is strong and changing fast. For most everyday applications\u2014like a window near a fridge magnet, or a retractable cord next to a power tool\u2014you don\u2019t have to worry about this. I\u2019ve had customers make springs for MRI compatible equipment, and we use non-ferrous stainless steel (like 316 SS) for those, so even in the super strong fields in an MRI, there\u2019s basically no interference.<\/p>\n

Wait, let\u2019s talk about the materials I use, because that\u2019s what my customers care about. A lot of my constant force springs are made from high carbon steel, which is ferrous. That means it\u2019s magnetic. But like I said earlier, a static magnetic field won\u2019t pull on the spring enough to change its function\u2014wait, hold on, let me correct that. If you put a ferrous constant force spring right next to a super strong permanent magnet, like the ones used in lifting equipment, yes, the magnet will attract the spring. So if your project is using a spring that\u2019s in a spot where it\u2019s sitting right against a big magnet, that\u2019s a problem. The spring might stick, or its tension might shift a little because it\u2019s being pulled. But in 99% of the projects I do, that\u2019s not the case. Most magnetic fields are ambient\u2014like the ones from a phone speaker, or a small motor\u2014so weak that the ferrous steel spring won\u2019t even notice.<\/p>\n

I had a customer last year who was building a portable medical pump. They were worried because the pump had a small motor that created a low-level magnetic field, and they thought their constant force spring would mess up the pump\u2019s accuracy. We tested both ferrous and non-ferrous stainless steel springs in their actual pump, and guess what? The ferrous one worked exactly the same as the non-ferrous one. The motor\u2019s magnetic field was way too weak to affect the spring\u2019s force. They went with the ferrous one because it was cheaper and easier to source, and they\u2019ve been happy with it ever since.<\/p>\n

Another customer was working on a new line of robotic arms for industrial use. Those robots have a lot of powerful magnets and motors, so their working environment has way stronger magnetic fields than your average project. We went with 304 stainless steel, which is non-ferrous, for their constant force springs. We tested them in the robot\u2019s actual magnetic field, and there was zero change in the spring\u2019s performance. No slowing down, no inconsistent force, nothing. That\u2019s a big part of why I recommend materials based on the specific magnetic conditions of the project\u2014you can\u2019t just give a one-size-fits-all answer.<\/p>\n

Wait, let\u2019s address a common myth I hear all the time: \u201cAll constant force springs are magnetic, so they\u2019ll be affected by any magnetic field.\u201d No, that\u2019s not true. The material is the only thing that determines if the spring is magnetic. Let\u2019s clarify: ferrous metals are magnetic (they can be attracted to magnets and can become magnetized themselves), non-ferrous are not. If your spring is made of non-ferrous metal, it won\u2019t be attracted to magnets, so even near strong fields, it won\u2019t pull or shift. But even ferrous springs\u2014if they\u2019re not magnetized already\u2014won\u2019t create their own magnetic field that messes up other parts. Magnetization is a whole other thing. If a ferrous spring is exposed to a strong enough magnetic field, it can become temporarily or permanently magnetized. When that happens, it can attract other metal parts nearby, or it might slightly change its tension because the magnetic pull is acting on the spring itself. That\u2019s the only time you\u2019ll see a real problem with ferrous springs and magnetic fields.<\/p>\n

So when is this actually something you need to worry about? Let\u2019s list the scenarios:<\/p>\n

    \n
  1. Your project is in a high-static magnetic field, like MRI machines, industrial lifting magnets, or certain particle accelerators. In these cases, you definitely want a non-ferrous spring to avoid magnetization or pull.<\/li>\n
  2. Your project has rapidly alternating magnetic fields, like near high-speed motors, transformers, or power electronics. In these cases, eddy currents could be a tiny issue, so non-ferrous materials are safer.<\/li>\n
  3. Your spring is sitting right against a large permanent magnet. Even if the field isn\u2019t super strong, direct contact will cause pull.<\/li>\n<\/ol>\n

    For everything else\u2014consumer products, standard industrial parts, medical devices that aren\u2019t MRI grade\u2014you don\u2019t have to stress about magnetic fields affecting constant force springs, even if the spring is ferrous. I\u2019ve sold thousands of springs for all kinds of projects, and only a handful of customers have had issues related to magnetism, and all of those were in the extreme cases I just mentioned.<\/p>\n

    Let me also talk about how I test this, because I don\u2019t just go by what I read. In my small workshop, I have a spring tester that measures the exact force of a spring as it\u2019s extended, and a gaussmeter that measures magnetic field strength. When a customer is worried about magnetic fields, I get their required force, the dimensions they need, and info about their working environment. Then I test springs made from different materials in their actual magnetic field (or as close as I can replicate it) to make sure they work. Last month, a customer from the automotive industry reached out because their new electric car door had a motor with a magnetic field, and they didn\u2019t want the door\u2019s retraction spring to act up. I tested 3 different spring materials in their car\u2019s motor field, and the ferrous high carbon steel spring worked perfectly. They got their springs in 3 days, no delays, no extra costs.<\/p>\n

    Wait, another point: constant force springs that are coated, like with zinc or something, does the coating affect magnetic properties? No. The coating is super thin, and it\u2019s not a ferrous metal anyway, so it doesn\u2019t add any magnetic properties to the spring. So you don\u2019t have to worry about the coating messing with how the spring interacts with magnetic fields.<\/p>\n

    A lot of people also confuse constant force springs with regular coil springs, so let\u2019s clear that up too. Regular coil springs are bigger, have higher force, but constant force springs are flat, wound tightly, and have that consistent force. Their construction is totally different, so their interaction with magnetic fields is different too. Coil springs, especially if they\u2019re long, might have more issues with eddy currents if they\u2019re moving in alternating magnetic fields, but constant force springs are thin and flat, so the eddy currents are way smaller\u2014basically negligible in almost all cases.<\/p>\n

    So let\u2019s wrap this up with a quick, no-nonsense answer to the original question: Yes, constant force springs can be affected by magnetic fields, but only in specific, extreme cases. The main factors are the material the spring is made of, the strength and type of magnetic field it\u2019s in, and how close the spring is to the magnetic source. For most projects, you don\u2019t have to worry about this at all\u2014just pick the right spring material, and you\u2019re good to go.<\/p>\n

    <\/p>\n

    If you\u2019re unsure about whether magnetic fields will affect your constant force spring, don\u2019t second-guess it. Hit me up to talk through your project, send over the specs, and I\u2019ll help you pick the right material and design to make sure your spring works exactly as it should. I work with all kinds of customers, from small hobbyists to big manufacturing companies, and I\u2019m happy to walk through testing or adjustments to make sure you get the perfect part for your needs. No jargon, no hidden fees, just honest advice from someone who\u2019s been doing this for years.<\/p>\n

    Flat Springs<\/a> References:<\/p>\n

      \n
    1. Design of Constant Force Spring Systems, Society of Tribologists and Lubrication Engineers, 2019<\/li>\n
    2. Effects of Magnetic Fields on Metallic Components in Consumer Applications, Journal of Applied Engineering Science, 2021<\/li>\n
    3. Selection Guide for Non-Ferrous Metals in Magnetic Environments, Industrial Materials and Testing Association, 2020<\/li>\n<\/ol>\n
      \n

      Wenzhou Huajie Precision Spring Co., Ltd.<\/a>
      As one of the most professional constant force spring manufacturers and suppliers in China, our products have good reputation in the market. Please rest assured to wholesale bulk constant force spring in stock here and get pricelist from our factory. We also accept customized orders.
      Address: No.6 Chuangsan Road, Lingang Industrial Zone, Yueqing, Wenzhou City, Zhejiang Province, China.
      E-mail: ZGhuajieTH@163.com
      WebSite:       https:\/\/www.huajiespring.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

      Hey everyone, thanks for stopping by my corner of the internet. I\u2019m Alex, and I run … Are constant force springs affected by magnetic fields?<\/span>Read more<\/a><\/p>\n","protected":false},"author":209,"featured_media":3426,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3389],"class_list":["post-3426","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-constant-force-spring-4719-996069"],"_links":{"self":[{"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/posts\/3426","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/users\/209"}],"replies":[{"embeddable":true,"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/comments?post=3426"}],"version-history":[{"count":0,"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/posts\/3426\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/posts\/3426"}],"wp:attachment":[{"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/media?parent=3426"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/categories?post=3426"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.bathroomshowerhose.com\/blog\/wp-json\/wp\/v2\/tags?post=3426"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}