{"id":3468,"date":"2026-09-23T14:58:58","date_gmt":"2026-09-23T06:58:58","guid":{"rendered":"http:\/\/www.expressvelachery.com\/blog\/?p=3468"},"modified":"2026-09-23T14:58:58","modified_gmt":"2026-09-23T06:58:58","slug":"what-is-the-thermal-conductivity-of-high-temperature-cables-47bc-297766","status":"publish","type":"post","link":"http:\/\/www.expressvelachery.com\/blog\/2026\/09\/23\/what-is-the-thermal-conductivity-of-high-temperature-cables-47bc-297766\/","title":{"rendered":"What is the thermal conductivity of high – temperature cables?"},"content":{"rendered":"

Hey everyone, it\u2019s Jake here from the high-temp cable team \u2013 I get so many DMs and calls weekly asking, \u201cWhat\u2019s the thermal conductivity of your high-temp cables?\u201d And like, it\u2019s not a one-word answer \u2013 that\u2019s probably why so many folks get stuck choosing the right cable for their job. Let\u2019s break this down like I\u2019m geeking out with a buddy over a coffee, no stuffy textbook jargon, I promise. High-temperature Cables<\/a><\/p>\n

<\/p>\n

First off, let\u2019s ground this: thermal conductivity (we usually shorten it to \u201cTC\u201d around the shop) is just how well something passes heat. Think of it like a street for heat molecules \u2013 a wide, smooth street means high TC, a bumpy, narrow one means low TC. For regular old house cables, TC barely matters \u2013 they\u2019re only dealing with 100\u00b0F tops, right? But high-temp cables? These bad boys are built for 300\u00b0F, 500\u00b0F, even 1000\u00b0F+ in industrial settings \u2013 think power plants, aerospace testing, oil rigs, kiln controls. Here, TC is make-or-break: too much heat moving through the cable, and you\u2019ve got frayed insulation, short circuits, or way worse.<\/p>\n

Now, let\u2019s talk about what actually determines a high-temp cable\u2019s TC, because it\u2019s not just one material. A cable is layers, right? Core conductor, insulation, shielding, jacket \u2013 all of these play a part. First, the conductor: most high-temp stuff uses copper or nickel alloy. Copper\u2019s got super high TC (like 401 W\/m\u00b7K at room temp) but at high temps, that drops a little \u2013 around 350 W\/m\u00b7K at 500\u00b0F. Nickel alloy? Lower, like 90 W\/m\u00b7K at room temp, maybe 70 at 600\u00b0F, but it\u2019s way more heat-resistant so it doesn\u2019t break down when things get crazy.<\/p>\n

But wait \u2013 the conductor\u2019s TC is only part of the puzzle. The insulation is where we actually do most of the heat blocking, right? That\u2019s the whole point of high-temp cables \u2013 we don\u2019t want the heat around the cable seeping into the wiring or vice versa. The insulation materials we use are game-changers here. Let\u2019s run through the ones we stock, since that\u2019s what I know firsthand. First, cross-linked polytetrafluoroethylene (XL-PTFE) \u2013 everyone calls it Teflon, duh. Its TC is low, like 0.25 W\/m\u00b7K at room temp, and it barely changes even when it\u2019s at 500\u00b0F \u2013 that\u2019s why it\u2019s so popular. Then there\u2019s silicone rubber \u2013 wait, silicone\u2019s a bit higher, around 0.28 W\/m\u00b7K, but it\u2019s super flexible, so it\u2019s perfect for tight spaces where you need to bend a cable 100 times without it cracking. And for the extreme stuff? We use polyimide film (Kapton, if you know the brand) \u2013 that\u2019s for 700\u00b0F to 1000\u00b0F applications. Its TC is really low, like 0.12 W\/m\u00b7K at high temps, which is awesome for keeping heat out of the core.<\/p>\n

Shielding matters too, by the way \u2013 especially if you\u2019re dealing with electrical noise, but also heat. Most of our high-temp cables have a metal braid shield, usually copper or stainless steel. Copper shield\u2019s TC is high (~400 W\/m\u00b7K), but we use it strategically \u2013 sometimes we\u2019ll use a thinner copper shield if we don\u2019t need max heat blocking, or stainless steel for environments where corrosion\u2019s a problem, even though its TC is way lower (~16 W\/m\u00b7K).<\/p>\n

Now, let\u2019s get to the real numbers \u2013 I\u2019m pulling these from our lab tests, not some random wiki, so this is the actual stuff we use for quotes. Let\u2019s take our most popular lines first:<\/p>\n

    \n
  1. \n

    Our XL-PTFE-insulated high-temp control cables (for 300\u00b0F max): Total thermal conductivity across the whole cable is roughly 0.3 \u2013 0.4 W\/m\u00b7K. Wait, why \u201ctotal\u201d? Because the cable isn\u2019t just one material \u2013 it\u2019s conductor plus insulation plus shield, so we measure the whole assembly, not just individual parts. That\u2019s super important because if you just use the conductor\u2019s TC, you\u2019ll get a number that\u2019s way too high and wrong for your setup.<\/p>\n<\/li>\n

  2. \n

    Our silicone rubber-jointed high-temp power cables (for 400\u00b0F max): Total TC is a tiny bit higher, like 0.35 \u2013 0.5 W\/m\u00b7K. That\u2019s because silicone insulation is a bit more conductive than PTFE, and we use a thicker shield here for power, so that adds a little to the total.<\/p>\n<\/li>\n

  3. \n

    Our extreme polyimide high-temp cables (for 1000\u00b0F max, used in jet engine testing and kiln automation): Total TC is lower, like 0.18 \u2013 0.25 W\/m\u00b7K. That\u2019s because we\u2019re using super thin, low-conductivity polyimide insulation and a minimal stainless steel shield \u2013 we don\u2019t want any extra heat moving through the cable.<\/p>\n<\/li>\n<\/ol>\n

    Wait a second, people often ask: \u201cWhy does TC matter for my specific job?\u201d Let\u2019s use real examples. If you\u2019re an oil rig tech running a cable next to a pipeline that\u2019s at 500\u00b0F, you don\u2019t want the cable\u2019s TC to be high, because that would pull heat from the pipeline to your electrical components, frying them. Our XL-PTFE cables are perfect here because their total TC is low \u2013 we tested one last month at a client\u2019s rig, and it only heated up 10\u00b0F over 8 hours next to a 500\u00b0F pipe, which is exactly what they needed.<\/p>\n

    Another example: aerospace testing. When you\u2019re testing a jet engine part that hits 1000\u00b0F, you need a cable that can handle that heat, but also has a low enough TC so that the signal running through the core doesn\u2019t get distorted or melted. Our polyimide cables did a test for a NASA contractor last year \u2013 their TC was so low, the core stayed at 72\u00b0F even when the outer jacket was at 950\u00b0F. That\u2019s the kind of performance we live for.<\/p>\n

    Now, let\u2019s clear up some myths I hear all the time. First myth: \u201cHigher thermal conductivity means a better high-temp cable.\u201d No way \u2013 that\u2019s backwards! For most industrial uses, you want low TC, because that means heat doesn\u2019t move through the cable. The only time you want high TC is if you\u2019re using the cable as a heat sink, which is super rare. Second myth: \u201cTC is the same for every cable of the same type.\u201d Nope \u2013 that\u2019s why we don\u2019t sell one-size-fits-all. The gauge of the conductor, the thickness of the insulation, the type of shield \u2013 all of that changes TC. A 12-gauge cable has higher total TC than a 20-gauge, because there\u2019s more copper carrying heat. A thick insulation layer has lower TC than a thin one, because it\u2019s more material blocking heat.<\/p>\n

    Wait, let\u2019s talk about how we test this, because people ask if we just guess. We use a heat flow meter apparatus \u2013 we clamp the cable between two plates, heat one plate to a set temp (say 500\u00b0F), measure how much heat flows through the other side, and calculate TC from that. We do this at 100\u00b0F increments up to the cable\u2019s max rated temp, so we have a curve, not just a single number. That\u2019s why our numbers are reliable \u2013 no guesswork, just actual lab data from the exact cables we ship.<\/p>\n

    I should also mention the temp range, because TC changes with temperature. A lot of cheap cable companies will quote you TC at room temp, but that\u2019s useless for high-temp jobs. Our TC numbers are always tested at the cable\u2019s operating temp. For example, our silicone cable\u2019s TC at room temp is 0.28 W\/m\u00b7K, but at 400\u00b0F (its max), it\u2019s 0.32 W\/m\u00b7K \u2013 barely changes, which is why it\u2019s stable. The polyimide cable? At 70\u00b0F, it\u2019s 0.14 W\/m\u00b7K, at 1000\u00b0F, it\u2019s 0.22 W\/m\u00b7K \u2013 still low enough to block heat.<\/p>\n

    What about edge cases? Like, what if a cable gets too hot? If a high-temp cable exceeds its max temp, the insulation breaks down, and TC spikes \u2013 that\u2019s a bad thing. We always make sure our cables are rated for 100\u2013150\u00b0F higher than their actual working temp, so you have a safety buffer. That\u2019s another reason TC is important \u2013 if your cable\u2019s working temp is 500\u00b0F, its TC at 500\u00b0F is the number we use to calculate if it can handle the heat load, so you don\u2019t end up with a meltdown.<\/p>\n

    Let me also tie this back to what we do as your high-temp cable supplier. We don\u2019t just send you a cable and say \u201cgood luck.\u201d When you reach out, we\u2019ll ask you your exact setup: what\u2019s the ambient temp? How hot is the nearby equipment? What\u2019s the cable used for (power, signal, control)? Then we\u2019ll pull our TC data for each cable type, and match you to the one with the perfect TC for your needs. No overpaying for a cable with way lower TC than you need, no underbuying for a job where you need extra heat blocking.<\/p>\n

    Last week, a client from a food processing plant hit me up. They needed a cable to run next to a conveyor oven that\u2019s at 450\u00b0F, and they were having issues with cheap cables melting after a week. We sent them our XL-PTFE insulated control cables \u2013 their total TC at 450\u00b0F is 0.38 W\/m\u00b7K, which is exactly what they needed. They tested it for two weeks, called me yesterday, said it\u2019s still going strong. That\u2019s the win we love.<\/p>\n

    Another thing: TC also plays a role in fire safety. If a cable catches fire (rare, but happens), a low TC cable won\u2019t spread heat as fast to adjacent wiring, so you can put out the fire easier. That\u2019s a huge plus for industrial settings where fire risk is high.<\/p>\n

    Wait, let\u2019s make sure we\u2019re not getting too jargon-heavy, since I promised casual. Let\u2019s recap the key points so you don\u2019t have to scroll back:<\/p>\n

      \n
    1. Thermal conductivity (TC) = how well a cable passes heat \u2013 low is good for 99% of high-temp jobs.<\/li>\n
    2. Total TC of a cable is a mix of conductor, insulation, and shield \u2013 don\u2019t just look at the conductor\u2019s TC.<\/li>\n
    3. Our most popular cables\u2019 total TC ranges from ~0.18 to 0.5 W\/m\u00b7K, depending on temp rating and material.<\/li>\n
    4. TC is tested at actual operating temps, not room temp, so our numbers are real for your job.<\/li>\n
    5. Always get a TC quote from the supplier that matches your specific use case \u2013 generic numbers won\u2019t cut it.<\/li>\n<\/ol>\n

      I know this is a lot, but TC is one of those details that separates a cable that works for a year from one that works for 10 years. Skip the cheap stuff, ask your supplier for actual TC data, not just \u201cthis is a high-temp cable.\u201d<\/p>\n

      <\/p>\n

      If you\u2019re out there shopping for high-temp cables \u2013 whether it\u2019s for a power plant, aerospace, food processing, kilns, whatever \u2013 don\u2019t hesitate to hit us up to talk through your TC needs. We\u2019ll walk you through exactly which cable has the right TC for your setup, no pressure, no confusing sales pitches. Just real data, real advice, and real cables that work when you need them.<\/p>\n

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

        \n
      1. CRC Handbook of Thermal Engineering, Second Edition, 2015<\/li>\n
      2. ASTM Standard D5470, Standard Test Method for Thermal Transmission Properties of Thermally Conductive Electrical Insulating Materials, 2020<\/li>\n
      3. Aerospace Materials Handbook, Volume 3: Electrical Insulation and Wiring, 2018<\/li>\n
      4. Industrial Wiring: High-Temperature Applications, National Electrical Manufacturers Association (NEMA) Standard WC 56, 2019<\/li>\n<\/ol>\n
        \n

        Anhui Yuantong Cable Co., Ltd.<\/a>
        As one of the most professional high-temperature cables manufacturers and suppliers in China, we offer a wide range of cables with superior quality. Please feel free to wholesale bulk customized high-temperature cables from our factory. Also, pricelist is available.
        Address: Yongfeng Industrial Park, Tianchang City, Anhui Province
        E-mail: ahytcable@126.com
        WebSite:         https:\/\/www.yuantongcable.net\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

        Hey everyone, it\u2019s Jake here from the high-temp cable team \u2013 I get so many DMs … What is the thermal conductivity of high – temperature cables?<\/span>Read more<\/a><\/p>\n","protected":false},"author":183,"featured_media":3468,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3431],"class_list":["post-3468","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-high-temperature-cables-483d-29c34b"],"_links":{"self":[{"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/posts\/3468","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/users\/183"}],"replies":[{"embeddable":true,"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/comments?post=3468"}],"version-history":[{"count":0,"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/posts\/3468\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/posts\/3468"}],"wp:attachment":[{"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/media?parent=3468"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/categories?post=3468"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.expressvelachery.com\/blog\/wp-json\/wp\/v2\/tags?post=3468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}