Parts You Should know: A Universe Of Useful Injection Molded Standoffs

Your clever branding won't work on me! *types caption in on iPhone*
Your clever branding won’t work on me!
*types caption in on iPhone, sips Starbucks*

I remember the first time I built a computer. My sister and I had our last fight about who would get to use the family computer, it was time I had one of my own. I knew a little bit, and I knew I wasn’t going to be one of those plebs that overpaid for a Gateway in its cow box. So I outsourced. One of the computer literate parents in my Scout Troop very kindly agreed to put together a list of components for me. I spent my Christmas money, birthday money, and a small mountain of money I had saved up. I remember getting the parts in the mail. I was so excited that a week earlier I had even bought one of those super lame computer tool kits to put it together.

I still remember how enormously frustrating the stand-offs for the mother board were to install. I think computers were still figuring out that they didn’t need ALL of the features of a mainframe. Anyway there was a 3mm screw on each side of a cm tall brass standoff. It also wanted me to put these little isolating paper washers on the assembly for some reason. Even with my then presidentially sized hands it took a long time. My Mom later told me that it was around this time she was certain the whole endeavour was going to end in tears.

Six hours of careful work later I had the computer together and running when I realized I had forgotten to buy an OS for it. She was nearly right.

Regardless. My early experience with computer assembly left me with a love for standardized screws, a hate for excessive fasteners, and a deep loathing for improperly routed wires. I was a weird kid. Anyway, when it came time for me to start designing my own enclosures for circuit boards I had all the unique psychological damage and underpinnings I would need to waste a lot of time googling on the internet for an alternate, screwless, method of standing a board off from a surface.

I eventually found a company that seemed to absolutely specialize in injection-molded snap or adhesive fit standoffs, card, and cable management components. Were there others like me out there? Best not to think about it…

Handier than you'd think. Just prep the surface first.
Handy. Just prep the surface first.

Anyway, you’ve probably bought some components from this company before and not even known it. For example, they are likely the manufacturer of those handy adhesive cable tie mounting posts you can buy at the big box stores.

Did you ever buy a nice motherboard that actually had a little cam clip to hold your PCI cards in place? It was probably made by them. They used to go by Robertson connectors, but have recently merged with some sort of conglomerate with a generic name called “Essentra components”

The real winner of their product line for me is their line of stand-offs. They have most sizes and configurations someone could want. They make for really quick reliable assembly. There’s zero chance of a screw coming loose and shorting something. Even if a standoff, broke it would only fill the enclosure with a bit of plastic. On top of that they put a constant force on the assembly. Unlike a metal stand-off they adjust a bit for manufacturing defects. Best of all, even if the fit is loose it will be copper against nylon, or nylon against steel. The chance of the stand-off damaging the circuit board is considerably lower than with common metal and brass assembly.  They also have a vibration dampening stand-off that I have a real fondness for.

The stand-offs are really great
The stand-offs are really great

Their line of plastic rivets are great for non-permanently fastening an enclosure shut. They have a removable kind, and also one that needs to be cut off. For low-load purposes they work just as well as a metal rivet, but are much less destructive when installed (won’t dimple your material) and look a bit cleaner to boot.

Lastly they have a truly phenomenal range of cable routing thingamajigs. There’s adhesive backed plates (it’s 3M VHB, if you clean with alcohol before you apply it sticks forever). There are through-hole snap fit rings. There’s every cable grip option imaginable available. Anything from the aforementioned pad to run a cable tie through, to a sort of U with ‘fists’ that you can snap a cable through. It’s great.

If you’re doing a lot of manufacturing or just want to see what’s out there, their catalog is great to look at. I wish I could point you in more directions. Essentra has swallowed up about four other companies in the last few years. There’s 3M and a few others who have part of their line, but nothing as vast. I imagine there are also a few competing import companies out there as well.

Do any of you use these in your work? Do you know of cool fasteners not commonly used? We’d love to hear about your secret supplier of standoffs and fasteners, and your favorite common or quirky go-to components. Sound off in the comments below.

59 thoughts on “Parts You Should know: A Universe Of Useful Injection Molded Standoffs

    1. I like simple yet multi-use fasteners. The screws with torx and a groove for a flathead. torx for fixing in your mancave and flathead MacGyver your way out with a coin from your wallet bashed with some stones to open the need to fix now device.

    1. Well, Gerrit has a point here. These kind of plastic parts are great. Perhaps not perfect for every job, certainly good enough for most. In the past there was a company called Skiffy, that is now called Essentra and they make lot’s of plastic wonderfull thingies. Their papaer catalog with most of their stuff was great to browse through.
      So… if you like it or not, I have to fully agree with Gerrit. This company has lot’s of stuff that’s interesting for any kind of engineer.

  1. “If you clean with alcohol before you apply it sticks forever”.

    No, not it doesn’t. They all will eventually release irregardless of surface preparation if there is any slight pressure on them or they are installed in any position but down. Also, you missed a word or a comma.

      1. http://www.merriam-webster.com/dictionary/irregardless

        Irregardless originated in dialectal American speech in the early 20th century. Its fairly widespread use in speech called it to the attention of usage commentators as early as 1927. The most frequently repeated remark about it is that “there is no such word.” There is such a word, however. It is still used primarily in speech, although it can be found from time to time in edited prose.

  2. double sided taped down cable tie anchors are shit. The double sided tape either lasts about 5 seconds before giving way or the foam of the tape degrades with time and they fall off. We glue or screw them down if using them at all. Doesn’t matter if you prep the surface with 99.9% IPA or sand the surface or whatever, they suck. Glue or screws

    As far as standoffs, if you have to make repairs often, threaded types are the best option, either male to female or female to female. Tapping your enclosure or place to mount and screw the male end into that, then you don’t have to fight screws or nuts on the other side, which may not be accessible in a complex device. But being able to take screw out on the board side is great, just make sure you leave room on your board for screw heads if doing your own layouts!

    We use everything from 4-40 nylon stand offs to 48 inch high voltage fiberglass or ceramics with half inch bolts and everything in between.

    Aluminum, delrin, nylon, ceramic, steel, so on and so forth.

    Vibration mounts…

    You name it.

    The style of standoffs that self clip are a pain in the ass if you have to change things more than twice, they always get fatigued and snap off, that is if you can get them to release in the first place. But it depends on your application. But friction fit has always been more trouble than its worth.

    People do things for hobby and they have limited exposure to what works and what doesn’t and its like being lost in the dark. But if you work in an industry for a few years, you quickly find out that there are millions of options engineers will come up with for a single problem, but only three of them really ever work 100% of the time.

    And 3D printing stand offs? you can buy the things 10 or 25 or 1000 at a time and each of those prices shipped is WAY less than the PLA or ABS and time you wasted printing for just about anything you’d need. Anything above that and the 3D printing is probably going to have weight bearing or HV standoff issues anyway.

  3. This article dates the author…buying an OS…sheesh! :-)

    I wanted kewl toys but could only afford surplus. The first and second computer I built was all surplus from Weirdstuff or Halted. Weirdstuff would strip the BIOS off their “as-is, guaranteed not to work, if it does you can return it for one that doesn’t” stuff. So I put a 286 BIOS into a 386sx board and had to live with it only recognizing 640k of RAM on the motherboard. Later I did obtain the correct BIOS, but by then I had an ISA ram expansion that slowed down the computer a bunch. I ran DR-DOS on that computer, back then it seemed like getting legit copies of software for free was easy. We also didn’t care about copying disks or having the same copy of software installed on multiple computers — it just wasn’t considered a problem.

    Today, with license keys on stuff, installing on multiple systems is pirating. The funny thing is that running Linux feels a lot like the old days where we didn’t care about sharing disks or software.

    I have a drawer absolutely filled with original floppies for all sorts of software, probably 500+ floppies in that drawer, all great stuff. It’s funny how Windows 3.0 wasn’t nearly as buggy and crash prone as today’s Windows.

      1. Speaking of electronics shops in the South Bay/Silicon Valley region, Anchor Electronics in Santa Clara (http://anchor-electronics.com/) is also a fun place to stop in. They’re a mix of new and a little salvage, and their prices are (of course) a little higher than what you’d find on the internet, but the value of having a brick and mortar store with their depth of inventory is hard to put a price on. They’re still “old school” in that their catalog is photocopied and stapled, and they do their checkout process by hand & adding machine, but they do accept credit cards with a reasonable minimum purchase. There’s a certain comfortable charm to the store that you don’t find around much these days. Great place for one-off parts, parts/adapters/components you didn’t know you needed, and components in bulk. Highly recommended stop if you’re in the area!

  4. I tend to 3d print my enclosures with built in standoffs and cable managment. The holes have to be around 2.4mm for a fine pitch 3m screw or around 2.6mm for a coarse thread one. For me the cost savings are down to time and distance. 1 hour wasted to go to the local place to buy hardware easily and gasoline and frustration because what I need is not in stock or needs to be modified. I simply design and 3d print my enclosures in ABS and be done with it. As for stick on pads etc etc, not my thing. I simply order 3 things in bulk. Zip ties in a range of sizes, 3m machine screws in bulk and heat shrink tubing in various sizes. No need to stock up on anything more unless I am making a production run.

    1. I came here specifically to mention Richco – then found out that it too has been swallowed by Essentra. I’ve known Richco for 25 years or so, but never heard of Essentra until now.
      One company that Essentra hasn’t bought is Bivar. One product line of theirs that I really like is the self-retaining PCB standoffs – http://www.bivar.com/enclosure-hardware/pcb-standoffs-board-supports/retaining-pcb-supports. They are easy to put on and take of, but have a bit of grip so they don’t fall off when you remove the screws holding down the PCB. Saves time and swearing – no chasing down mounting screws and standoffs from the innards of what you’re working on or whatever dark corner of the floor they rolled / bounced to.

      BTW, I happen NOT to like those plastic standoffs that just push into the board holes. When removing a board, keeping pliers in just the right location so you pinch the tabs without the standoff rotating can take a few attempts. Then, when you go to release the next standoff, the one you just released may pop back into place. I service equipment that uses these, and I find then to be a PITA. Magnetic screwdrivers and steel screws FTW.

  5. Some of those adhesive cable tie anchor points also have a countersunk hole in the center. I used a lot of these and 4mm countersunk machine screws to hold the fixed cabling on my CNC router. The counter sunk screws are low and don’t interfere with the cable tie path.

    I found the standoffs that my local electronics shop sell always require a larger hole that is in the case or PCB. Most holes are 3mm or 1/8″, but most standoffs require 4mm or whatever the next imperial size up is.

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