Some things are so common you forget about them. How often do you think about an ordinary resistor, for example? Yet if you have a bad resistor, you’ll find it can be a big problem. Plus, how can you really understand electronics if you don’t know all the subtle details of a resistor? In the mechanical world, you could make the same arguments about the washer, and [New Mind] is ready to explain the history and the gory details of using washers in a recent video that you can see below.
The simple answer is that washers allow a bolt to fit in a hole otherwise too large, but that’s only a small part of the story. Technically, what you are really doing is distributing the load of a threaded fastener. However, washers can also act as spacers or springs. Some washers can lock, and some indicate various things like wear or preloading conditions.
Plain washers have a surprising number of secondary functions. Spring washers, including Belleville washers, help prevent fasteners from loosening over time. Wave washers look — well — wavy. They provide precise force against the bolt for preloading. Locking washers are also made to prevent fasteners from loosening, but use teeth or stops instead of springs.
There are plenty of standards, of course, that mostly match up. Mostly.
If you like knowing about odd washers, you might also want to know about the bolts that pass through them.
Really never expected to see a photo of a machine tool drawbar on Hackaday.
Forbidden machinist lore goes deep!
When you try to make it sound like some secret knowledge but it’s actually stuff taught during second semester at university, right after first semester calculus weeds out those not interested in studying what they’ve signed up for.
wow this dude must have aced washers 125
No it isn’t taught. Know how I know? There are still people at the end who don’t know you need to use an Allen key to tighten an Allen socket head bolt. I wish I was kidding.
Maybe to mechanical and industrial engineering folk. Us computer and software people are lucky to get a few classes of machine shop
They even replaced the microcontroller workshop with a software engineering workshop in my curriculum the year it was supposed to be held. The only hardware I had to touch to get my CS degree was a keyboard.
Who needs a washer when you use a self-sealing stem bolt. 😁
A DS9 fan, I see…
I thought this was an article on washing machines.
“Spring washers, including Belleville washers, help prevent fasteners from loosening over time”
Well, not really :-)
https://youtu.be/IKwWu2w1gGk?feature=shared
Yeah, especially b/c the header image is showing belleville washers in a typical application (what looks like applying a preload closing force to a spring collet), which is not about preventing fasteners from loosening over time!
Yeah, most lock washers (or Belleville washers being used as lock washers) are next to or worse than useless. There’s a NASA paper that digs into it in a less marketing-ey way. I can’t find it right now, but their fastener design manual goes over the highlights https://ntrs.nasa.gov/api/citations/19900009424/downloads/19900009424.pdf
When he said its obvious what they do I thought yeah it is and hit the stop button.
I’m glad to see all these expert commenters stop by from hackaday’s sister website washer-a-day.