this post was submitted on 04 Oct 2025
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What is this thing?
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Machinist here
This all looks custom for the product
While I will admit I have seen nuts and washers akin to those in the photo, it’s clear to me that the hardware is custom made based on the finishes presented on the face of the flat bolt.
The bolts’ rotation is being held still by ‘grips’ or ‘teeth’ on the bottom side of the bolt head and to the shoulder of the mating face with the washer. The washer is also rotationally helping the bolt stay stationary, with similar teeth features. Beyond all this, the faces of the blades are simply ground flat, so even without a bearing shim or other bearing mechanism, the blades will slide smoothly past one another.
See tooth lock washers on McMaster And plow bolts on McMaster
Again it’s going to be hard to find any product that directly represents what you see In the photo.
That style of nut with two flats on it is common on scissors, but I'll be damned if I know what they're called on a technical level. And that's unusual, because I managed a hardware store for some time and handled (not to mention ordered) an awful lot of random specialty fasteners in my years.
The washers/bushings with the frilly edges are purely decorative. There is no reason these couldn't be a flat washer, and the ruffles around the circumference don't do anything mechanical. They're pretty common on the hardware sets used on scissors. See also here, for instance. It's temping to think that they're acting like a toothed lock washer, but they aren't. Usually they stay put relative to the bolt head and nut, but the scissor blades will slide freely underneath as they pivot.
The underside of the bolt head and its attendant nut are also most likely flat. They are on all the shears I've ever taken apart, at any rate. You'll probably find a split lock washer under one or the other of them, though.
The two blades of a pair of scissors have to slide squarely past each other and maintain a point of contact, so it's very rare to find any washer or spacer between them. Another related semi-useless fact: If you carefully peer down the edge of a pair of scissors or cheat and use a straight edge on them, you'll find that most scissor blades are in fact curved. This is so the blades only have one point of contact at a time, which moves up and down their length as you open and close them. This results in a noticeable gap at some point along their length when they're closed, as is visible in your picture. This is not indicative of an alignment issue.
Edit: On the topic of undoing these, and why there is no driver head on one side. The shoulder of the bolt is squared on that side, and engages with a square hole present in one scissor blade, but not in the other. There's no need to grab the bolt head with anything. You can engage the nut with a normal adjustable wrench, but there are pretty good odds you'll discover some asshole peened the end of the bolt making it tough to get the nut off, and doubly so without damaging anything.
This was an unexpectedly fascinating technical read. Admittedly, I'm "watching" baseball so take my definition of fascinating with a grain of salt.
o7