ALLEN NUTS ever used or tried them?

[thaiguzzi]

Learn something new everyday.
Never heard of, or seen them before, and i've been a m/c mechanic for over 30 years.

[wierdscience]

They show up on tie rod type air cylinders all the time.Usually the models designed to accept various flat stacked end mounts.I have also used them when I needed an Alllen socket head solution,but had a required length greater than the maximum available bolt length.

[H380]

I love the 12pt stuff.

You can see the wrench/socket clearance you gain. They are custom ARP polished SS and almost $9 each.

[754]

I already knew from the beginning, their use is limited, and they are expensive. And they Will never be a replacement for a co mom fastener. And it keeps being brought up.
I am writing this because, it keeps being compared to nuts suitable for regular use.
Once in a while it's a great solution. The only alternative in my case would have been an even longer one-off nut from hex, with most of the hex turned off to fit in the whole. Then the full hex would have been sticking out proud and ruined the look.
It was being used on a multi diameter, double threaded stud that was an upper shock mount

[Peter.]

Yamaha used these for exhaust stud nuts on some of their XS and XJ motorbike range. They were good at preventing the dreaded snapped exhaust stud. I bought a xj1100 that had been stood in a garden for 7 years uncovered and all the nuts came loose right away.

[A.K. Boomer]

We use the external 12 point head screws at work since they require much less clearance for the socket tool and screws can be positioned closer together. These alloy screws are some of the best and strongest screws I've ever seen. The biggest one we use is 1-1/4". We torque them close to the material yield and have never strip the head.

I like those, Honda uses them on some of their connecting rods, also head bolts.

they will only work with a 12 point socket but they work very well because all 12 points of contact...

[Paul Alciatore]

They make inserts that can be pressed into a hole that do not have the internal hex for driving them - which is not needed for that use. I suspect they cost a lot less.

Again, McMaster prices:

1/4-20:
Press fit for sheet metal: $0.3232 each
For thicker panels: $0.588 each

M5:
Press fit for plastics and soft metals: $0.6555 each

Just some sample prices, they have many more. They are expensive, but the most expensive of them seem to be around half the price of the Allen Nuts.

It costs a lot to make that internal hex on one end with the threads on the other. If you are going to use them as an insert, it would be better to purchase one made for that use. Not only would it be less expensive, but it will probably grip better than the small knurl on the Allen Nuts. "Won't turn" is a relative term. I have seen many pressed in nuts that came loose. If you are depending on a knurl, you will probably have to use a reamer to get the hole size spot on.

I suspect that knurl on the Allen Nuts is for gripping with the user's fingers to get them started.

I am not deliberately trying to rain on your parade, but it seems to me that the applications for the Allen Nuts, while they do exist, are very limited. And their price does not help that situation. Over 50+ years I can't really recall any situations where I have seen them in use.

I brought it up mainly, because it eliminates the gaping hole around a countersunk fastener that uses nut and washer.
And the fact that in can be pressed into a hole an won't turn .
Not suggesting it's a replacement for every nut out there.

[mikey553]

We use the external 12 point head screws at work since they require much less clearance for the socket tool and screws can be positioned closer together. These alloy screws are some of the best and strongest screws I've ever seen. The biggest one we use is 1-1/4". We torque them close to the material yield and have never strip the head.

[754]

I brought it up mainly, because it eliminates the gaping hole around a countersunk fastener that uses nut and washer.
And the fact that in can be pressed into a hole an won't turn .
Not suggesting it's a replacement for every nut out there.

[A.K. Boomer]

You guys would debate the usefulness of a ham sandwich.

-D

It's true allot of these guys (admittedly me too) bring up the finer details esp. when it comes to all the variables with things that hold our inanimate lives together, things like fasteners,,, so you might want to just sit this one out

[A.K. Boomer]

Allen nuts are very limited and have to also rely on very strict stud lengths or you run the risk of not grabbing enough threads or running the stud in too far and not having much allen surface for tightening... in some cases depending on pitch of course one might have to hold + or - one thread...

conventional bolt methods have vast forgiveness in this area and conventional nut methods that use studs always shoot for overkill in length for as long as the stud has threaded area there's no worries in either direction.

Therefor - if space is still a factor and the design is of your own or something your trying to improve upon you may be better off with an allen bolt of proper length as it will take allot of the guess work out of things like flange thickness with possible thick gasket material and it's effects under compression.

[Mcgyver]

You guys would debate the usefulness of a ham sandwich.

-D

white or rye?

[Ed ke6bnl]

Yes, I would have rather had 6 point.
I had an excellent supplier for chromed fasteners for bike stuff, I was buying these in chrome, man they did look good.
Cost has always been high. I think the chrome 3/8 NF were like 4 or 5 bucks in the 90,s. Still got a few around.

they maybe what VW use and called triple square.

[Doozer]

You guys would debate the usefulness of a ham sandwich.

-D

[HudsonMC]

For attaching two flat surfaces together where space for the fastener might be an issue, like the exhaust header example given earlier, I like the left hand/right hand fasteners. I don't know what they're called, but it's a short fastener with male LH threads on half it's length and male RH threads on the other half. There is a female Allen hex in the top. Hole in the topmost flange only needs to be large enough to pass the hex wrench. When the fastener is turned clockwise, it draws the two flanges together.