| Science Forum Index » Mechanics Forum » Q: Looking for source for this unusual fastener... |
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| Jon Juhlin... |
 Posted: Wed Nov 04, 2009 10:33 pm |
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Guest
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I recently encountered as special nut or nut-like fastener and it is just
the thing for a particular application where a bolted connection needs to be
cinched up once and provide a connection that can't be disassembled.
The joint I observed used a 3/4" unc bolt that appeared to be nothing out of
the ordinary. But the nut was a conical affair that is either crimped on or
pressed on in a way that the threads of the nut are damaged during the
pressing process such that the nut can't be removed. The appearance of the
device suggests that is pressed on rather than crimped, but is in a tight
spot where I can't see.
I saw them used in a hinged connection on a floating boat dock, where the
bolt served as the pin in the hinge between dock sections. The attractive
part of the conical non-removable nut was that it discourages fun loving
local teenagers from disassembling the dock and sailing away on the
disconnected sections. Indeed I have been asked to make repairs to the dock
after just such an attempt was foiled by these handy devices and the
miscreants decided to vandalize the dock as a way of teaching it a lesson.
I need to take the dock apart but would like to reassemble it with these
handy gadgets.
I assumed it was made by Huck fasteners because it appeared to be distantly
related to a Huck bolt other than it was not as heavy duty and could be
installed in tight quarters where a Huck gun could not go.
Any suggestions on where I could find this would be appreciated. I tried
Fastenal, but they do not list this device.
Jon Juhlin |
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| dlzc... |
| Posted: Thu Nov 05, 2009 8:36 am |
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Dear Jon Juhlin:
On Nov 4, 8:33 pm, "Jon Juhlin" <j_juh... at (no spam) efn.org> wrote:
....
[quote]The joint I observed used a 3/4" unc bolt that
appeared to be nothing out of the ordinary. But
the nut was a conical affair that is either crimped
on or pressed on in a way that the threads of the
nut are damaged during the pressing process
such that the nut can't be removed.
[/quote]
Probably better to look for "tamper proof fasteners", such as:
http://www.tufnutworks.com/category.aspx?id=1
Other options might be:
1) left hand threads (it sure gets me...)
2) drill through the bolt behind the nut
3) two sledgehammers, one on head of bolt, one peens the threaded end
over.
4) explosive bolts...
David A. Smith |
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| brian whatcott... |
| Posted: Sat Nov 07, 2009 8:18 pm |
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Guest
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Jon Juhlin wrote:
[quote]I recently encountered as special nut or nut-like fastener and it is just
the thing for a particular application where a bolted connection needs to be
cinched up once and provide a connection that can't be disassembled.
The joint I observed used a 3/4" unc bolt that appeared to be nothing out of
the ordinary. But the nut was a conical affair that is either crimped on or
pressed on in a way that the threads of the nut are damaged during the
pressing process such that the nut can't be removed. The appearance of the
device suggests that is pressed on rather than crimped, but is in a tight
spot where I can't see.
I saw them used in a hinged connection on a floating boat dock, where the
bolt served as the pin in the hinge between dock sections. The attractive
part of the conical non-removable nut was that it discourages fun loving
local teenagers from disassembling the dock and sailing away on the
disconnected sections. Indeed I have been asked to make repairs to the dock
after just such an attempt was foiled by these handy devices and the
miscreants decided to vandalize the dock as a way of teaching it a lesson.
I need to take the dock apart but would like to reassemble it with these
handy gadgets.
I assumed it was made by Huck fasteners because it appeared to be distantly
related to a Huck bolt other than it was not as heavy duty and could be
installed in tight quarters where a Huck gun could not go.
Any suggestions on where I could find this would be appreciated. I tried
Fastenal, but they do not list this device.
Jon Juhlin
Tufnut? Breakaway Nut?[/quote]
http://www.tufnutworks.com/category.aspx?id=1
Spanner nut?
http://www.hudsonfasteners.com/security.htm
Brian W |
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| DD_BobK... |
| Posted: Thu Nov 12, 2009 6:42 pm |
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Guest
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On Nov 4, 7:33 pm, "Jon Juhlin" <j_juh... at (no spam) efn.org> wrote:
[quote]I recently encountered as special nut or nut-like fastener and it is just
the thing for a particular application where a bolted connection needs to be
cinched up once and provide a connection that can't be disassembled.
The joint I observed used a 3/4" unc bolt that appeared to be nothing out of
the ordinary. But the nut was a conical affair that is either crimped on or
pressed on in a way that the threads of the nut are damaged during the
pressing process such that the nut can't be removed. The appearance of the
device suggests that is pressed on rather than crimped, but is in a tight
spot where I can't see.
I saw them used in a hinged connection on a floating boat dock, where the
bolt served as the pin in the hinge between dock sections. The attractive
part of the conical non-removable nut was that it discourages fun loving
local teenagers from disassembling the dock and sailing away on the
disconnected sections. Indeed I have been asked to make repairs to the dock
after just such an attempt was foiled by these handy devices and the
miscreants decided to vandalize the dock as a way of teaching it a lesson.
I need to take the dock apart but would like to reassemble it with these
handy gadgets.
I assumed it was made by Huck fasteners because it appeared to be distantly
related to a Huck bolt other than it was not as heavy duty and could be
installed in tight quarters where a Huck gun could not go.
Any suggestions on where I could find this would be appreciated. I tried
Fastenal, but they do not list this device.
Jon Juhlin
[/quote]
These might be over kill but .................
http://www.hi-shear.com/fastener_hl.htm
cheers
Bob |
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