{"id":3506,"date":"2026-09-29T05:56:06","date_gmt":"2026-09-28T21:56:06","guid":{"rendered":"http:\/\/www.tauaja.com\/blog\/?p=3506"},"modified":"2026-09-29T05:56:06","modified_gmt":"2026-09-28T21:56:06","slug":"are-3-50mm-pitch-connectors-available-in-through-hole-designs-4a6a-6a0476","status":"publish","type":"post","link":"http:\/\/www.tauaja.com\/blog\/2026\/09\/29\/are-3-50mm-pitch-connectors-available-in-through-hole-designs-4a6a-6a0476\/","title":{"rendered":"Are 3.50mm Pitch connectors available in through – hole designs?"},"content":{"rendered":"

A few months back, I was sitting across from a customer in our office, walking through a design review for a medical device they were wrapping up. They\u2019d flagged a small but critical snag: their current connector selection for the unit\u2019s power distribution was all surface-mount, but their assembly team was struggling with the inconsistent solder joint reliability of SMT parts on their thick, high-Tg PCB. \u201cWe need through-hole,\u201d they said, leaning in, \u201cbut we can\u2019t switch pitch\u2014we designed everything around 3.50mm.\u201d That conversation stuck with me, not just because it was a potential order, but because I\u2019ve fielded that exact question dozens of times since I started working with 3.50mm pitch connectors 12 years ago: Are 3.50mm pitch connectors available in through-hole designs? 3.50mm Pitch<\/a><\/p>\n

<\/p>\n

Let me cut straight to the answer first, because that\u2019s what most engineers and procurement teams want to know before they dig into details: Yes\u2014they absolutely are. But like a lot of connector specs, the \u201cyes\u201d comes with a few important caveats that only someone who works with this pitch every day can walk you through, not a generic part catalog or a 10-second Google search.<\/p>\n

First, a quick refresher on why 3.50mm pitch is so common in the first place, because that context explains why through-hole versions matter so much. For new readers, pitch is the distance between the center of one connector pin and the center of the next\u20143.50mm is roughly 0.138 inches, right in that sweet spot between fine-pitch connectors (which are too delicate for power and heavy signal loads) and larger pitches that take up too much board real estate. We see it everywhere: industrial control panels, medical sensors, consumer appliance power supplies, even some automotive auxiliary systems. When engineers pick 3.50mm, it\u2019s usually because they need a connector that can carry 5A to 15A per pin, has enough space for wire crimps that can handle vibration or temperature swings, and doesn\u2019t waste board space on a wider pitch.<\/p>\n

For a long time, though, through-hole versions of this pitch were either afterthoughts or inconsistent, which is why so many people still associate 3.50mm exclusively with SMT. Early SMT 3.50mm parts popped up in the 1990s, designed for high-volume consumer electronics where SMT assembly was faster and cheaper. Through-hole was seen as old tech, relegated to hobbyist projects or prototyping, and connector manufacturers didn\u2019t invest much in refining 3.50mm through-hole lines. That started to change around 2015, though, when two big trends shifted demand: first, the rise of industrial IoT, where equipment is deployed in dusty, high-vibration environments where SMT solder joints have a higher failure rate, and second, a renewed focus on high-reliability medical devices, where through-hole connections are still the gold standard for permanent installations because they don\u2019t delaminate from PCB copper layers the way SMT joints can.<\/p>\n

By 2020, we saw a measurable jump in requests for 3.50mm through-hole connectors, and by 2022, our own product team finished refining our line to address the gaps we\u2019d seen in older models. Let\u2019s talk about what makes a good 3.50mm through-hole connector, because not all of them are equal\u2014and that\u2019s a big part of why the answer isn\u2019t just \u201cyes\u201d or \u201cno.\u201d<\/p>\n

One key difference is the pin design. Older through-hole 3.50mm parts used straight, single-prong pins that you jammed through a PCB hole and soldered on the other side. The problem with those is that they have almost no strain relief, and the solder joint is only as strong as the amount of solder you can apply. Modern through-hole 3.50mm connectors use what we call \u201cright-angle crimp pins with a flange\u201d \u2014 the pin has a small, flat flange that sits flush against the top of the PCB once you insert it, which creates a bigger surface area for solder. That means the joint is less likely to crack if the board gets bumped or flexed, which is a huge win for industrial and medical applications. We also spec our pins from brass alloy with a nickel-tin plating, which gives better corrosion resistance than the tin-lead plating some cheaper parts use, so they last longer in environments with high humidity or chemical exposure.<\/p>\n

Another big factor is the housing design. 3.50mm pitch requires housings that are durable enough to handle repeated mating and unmating, and through-hole housings have to account for the pins\u2019 position on the board. We use high-temperature nylon (UL94 V-0 rated, for anyone who needs that compliance) that can handle soldering temperatures up to 260\u00b0C for 10 seconds, which is standard for lead-free assembly. A common mistake we see with cheap 3.50mm through-hole parts is that their housings melt during reflow soldering, which ruins the entire board. Our line is tested for that specific issue\u2014every batch goes through three consecutive reflow cycles with no housing distortion, which is a non-negotiable for our industrial and medical customers.<\/p>\n

Wire compatibility is another point that comes up a lot. 3.50mm pitch crimp terminals are sized for 22AWG to 14AWG wire, which is perfect for the power loads this pitch is intended for. But through-hole versions have to line up so that the crimp terminal\u2019s opening is aligned with the back of the housing, so you can crimp the wire and then snap it into the connector without forcing it. We made our housings with a simple wire retention latch, so you don\u2019t need extra tools or adhesive to keep wires from pulling out\u2014something we heard multiple customers complain about with older through-hole models.<\/p>\n

Now, let\u2019s address the exceptions, because there are cases where 3.50mm through-hole isn\u2019t available, and that\u2019s important to know too. If you need a very high pin count\u2014like 30 pins or more\u2014you might struggle to find 3.50mm through-hole. The housing width gets too large, and the pins are so close together that through-hole assembly can cause bridging during soldering. For those high-pin-count applications, most manufacturers will suggest a 5.08mm pitch through-hole instead, which has more space between pins. Another exception is if you need a super-low-profile connector for wearables or small consumer devices. 3.50mm through-hole parts are usually at least 8mm tall when mounted on a PCB, which is too big for tiny devices where height is critical. But for most heavy-duty applications\u2014power supplies, motor control, sensor interfaces\u20143.50mm through-hole is fully available.<\/p>\n

I mentioned that customer from a few months back, the medical device team. We worked with them to adapt our standard 3.50mm through-hole line to their needs: they needed 20 pins, a keyed housing to prevent reverse mating, and compliance with IPC-A-610 Class 3, the highest standard for high-reliability electronics. We were able to deliver samples in two weeks, and their first batch of prototypes passed all vibration and temperature testing with zero issues. They placed a full order last month, and they\u2019re already talking about expanding the line for their next product. That\u2019s the kind of work that makes all the late nights in product development worth it.<\/p>\n

If you\u2019re reading this and wondering if a 3.50mm through-hole connector will work for your project, here\u2019s a quick checklist to walk through. First, confirm your load requirements: if you\u2019re carrying more than 15A per pin, you might need a larger pitch, but 3.50mm works for most common applications. Second, check your assembly process: do you need through-hole specifically because SMT joints aren\u2019t reliable enough? If yes, make sure the connector is rated for reflow soldering, not just wave soldering, because most modern PCBs use reflow. Third, check compliance: if your product has to meet UL, IPC, or medical standards, don\u2019t skimp on the cheaper parts\u2014they might not have the right certifications.<\/p>\n

<\/p>\n

At the end of the day, the question of whether 3.50mm pitch through-hole connectors are available is about more than just a part number. It\u2019s about matching your connector to your application\u2019s needs, avoiding the pain points that come with older, poorly designed parts, and working with a supplier that understands both the specs and the real-world challenges of assembly. If you\u2019re working on a design right now and stuck on connector selection, or if you\u2019ve had bad experiences with through-hole parts in the past, our team is here to help. We don\u2019t just sell connectors\u2014we work with engineers and procurement teams to find the right fit, whether that\u2019s our standard 3.50mm through-hole line or a custom adaptation for your specific project. Reach out to our team to discuss your requirements, and we can share samples, compliance documents, and technical specs to make sure your design gets the reliability it needs.<\/p>\n

0.60mm Pitch<\/a> REFERENCES<\/p>\n

    \n
  1. IPC-A-610, Acceptability of Electronic Assemblies<\/li>\n
  2. UL 94, Standard for Safety for Flammability of Plastic Materials for Parts in Devices and Appliances<\/li>\n
  3. Connector Industry Association (CIA) 2023 Market Report for Heavy-Duty Interconnects<\/li>\n<\/ol>\n
    \n

    Dongguan Yinglian Electronics Co., Ltd.<\/a>
    We’re well-known as one of the most professional 3.50mm pitch suppliers in China. With abundant experience, we warmly welcome you to buy bulk advanced 3.50mm pitch made in China here from our factory. If you have any enquiry about cooperation, please feel free to email us.
    Address:
    E-mail: James@csg-china.com
    WebSite:     https:\/\/www.csgconn.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    A few months back, I was sitting across from a customer in our office, walking through … Are 3.50mm Pitch connectors available in through – hole designs?<\/span>Read more<\/a><\/p>\n","protected":false},"author":143,"featured_media":3506,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3469],"class_list":["post-3506","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-3-50mm-pitch-4410-6a3ee2"],"_links":{"self":[{"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/posts\/3506","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/users\/143"}],"replies":[{"embeddable":true,"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/comments?post=3506"}],"version-history":[{"count":0,"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/posts\/3506\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/posts\/3506"}],"wp:attachment":[{"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/media?parent=3506"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/categories?post=3506"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.tauaja.com\/blog\/wp-json\/wp\/v2\/tags?post=3506"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}