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Incorrectly rolled 1/2"-13 bolt

opscimc

Stainless
Joined
Jan 24, 2012
Location
Southwest
I came across something today I had never seen before. After failing to get a 1/2"-13 bolt started in a nut that I knew was good (because another 1/2"-13 bolt had no trouble with it), eventually I realized the threads were rolled in circles, rather than in a helix. To make sure my eyes weren't deceiving me I spun it in the lathe. A good 1/2"-13 bolt held up against it meshes nicely, so the problem is only apparent when looked at closely. Maybe others have come across such defective bolts in the past, but in all the fasteners I've used in all the years I've been using them, this was a first for me.
 
I have a collection of bolts and other mistakes that made it to me kind of interesting really.

Now be truthful how many times did you try to start it before you gave up.

I had a tierod once that was like that and tried for a least 1/2 hour to start it .
 
Now be truthful how many times did you try to start it before you gave up.

Hah Hah..... I bet If I had had it that I would have tried for quite a while if it was a tricky spot where I had to do it by feel.......it would just seem I just hadn't got it aligned quite right..... if I could SEE it not going on, I'd have much less patience....
 
They do make circular thread bolt that the nut is crimped on and all it will do is spin when someone tries to take it off.

These are called Huck Bolts I believe. They are very common in truck chassis. You have to torch them apart.

It is possible the OP got one mixed in with his bolts.
 
I've see this exactly once in forty-some years messing with mechanical stuff, and it was a long time ago. I was beginning to doubt my memory.
 
Yup, saw it many years ago myself. Came in a box of bolts that were other wise fine. I guess the thread roller had a jam up of some kind and it couldn't advance or something of that nature. Wish I would have kept mine.
Bill
 
I've never seen this one, but arace mechanic I knew has a collection of weird things - most much eaiser to spot - I've seen a few - bolts with no threads, socket-head-cap-screws with no socket space, eye bolts with no eye-hole, nuts with no thread inside, etc.
 
Now be truthful how many times did you try to start it before you gave up.
Actually, it was pretty fast. I was assembling a Unistrut bracket and the bolt wouldn't start. I assumed there was a slight problem with the thread at the end of the bolt so I put a nut in the vice and tried to run the bolt into it. No go. So I next was headed to the grinder to deal with the end so I examined the thread closely to see where it started. That's when I saw there was no start. I still couldn't believe what I was seeing so I put it in the lathe to spin it. From start to finish it couldn't have been more than a couple of minutes.

As for it being intentionally made that way, I have at least a half-dozen just like it, all marked with a raised 'J' on the hex head.
 
Kind of hard to figure out how that would happen...I have somewhere a set of thread rolls my dad got at an auction, and they have a thread on them, hard to picture how they could make annular rings around a part ?? I could see them ripping the threads all off if motion was inhibited somehow. I think I have seen a movie of a bolt header at work and it used two flat plates with threads on them to roll the threads ?

Bill
 
Had one in either 8 or 10 mm that was a fairly decent left hand thread! Not true to spec left hand but a good try.

Came in the kit of parts for an economy mortice attachment that I took in exchange for a small job. Wondered why there were four "identical" bolts for four holes and one "ex scrap box" nut and bolt until the penny dropped that teh offending lefty like one wouldn't screw into any of the proper nuts.

Clive
 
I'm hoping you kept it as a "souvenier" :)

A few years ago I bought some "frames" of beer in Germany. I'm not far from the German border and beer is cheaper there (even Danish beer) than here. BTW a "frame" of beers is 24 bottles or cans - in this case cans.

Anyway after a few beers back home (not on the same day :)) one can only weighed half as much as it should. I wrote to the German brewer and was informed that this was impossible as everything was double checked. Neverttheless they did send me a free frame of beers as an apology. A few cans later (from the original frames) and I found another one :) I then weighed all the cans I had and found 3 more. I sent 2 of the unopened cans to the brewery as they obviously hadn't believed me first time and received yet another free frame of beers. No apology though :D

I didn't know whether to be offended that they hadn't believed me first time or greatful that I'd received 48 beers :D A bit of both LOL

Gordon

The so called "long neck" beer bottles here from a bar are recycled over and over, and you can and do find things like swizzle sticks, and even cig butts in one now and then. Probably sterile but still not a pleasant "bonus" :-).

Bill
 
I had a 1/2-13 stud from a mill clamping set that was like that. One of my students was getting set to rethread it with a die and I took a look at it and had a good laugh and then taught him about thread rolling.
 
I got a junk batch of J bolts when doing my last building addition. I never tried the nuts, just handed them to the concrete guys. After its up the steel crew could not start anything but the B7 alloy rods in other parts of the foundation were ok. Wound up making a tool to hold a 2 inch die that could be turned with a ratchet to chase it down to the concrete. I still have a couple of those j bolts.... doubt I'll ever put one in concrete again without inspecting it. It woulda been a LOT easier to chase in a lathe
 
My dad had a jar of improperly made parts, like what others have mentioned. With modern manufacturing equipment, I don't see nearly as many as I did years ago.
 
I have a Cat track bolt that has a huge cold shut running the whole length of it. 5/8 dia, oversize head, grade 8, and it looks a lot like a big cotter pin with threads. Threads are fine.
 








 
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