The pillar-drill thread finally prompted me to get some T-nuts (the sort
that slide in a slot, not the spiky ones) so I can fix my little
vice/clamp properly to the pillar-drill's table.

I was surprised to find the nuts weren't tapped all the way through. The
supplier said they are all like that, so the bolts have to be exactly
the right length. Is that true? It means the bolts have to be
pretty-much exactly the right length.
--
Reentrant

On Jul 26, 2:33*pm, Reentrant wrote:

I was surprised to find the nuts weren't tapped all the way through. The
supplier said they are all like that, so the bolts have to be exactly
the right length. Is that true? It means the bolts have to be
pretty-much exactly the right length.

You're not supposed to use a bolt, you use a stud with a nut and
washer on top.
Nothing to stop you tapping them all the way through. The reason
they're made that way is so that you don't distort the slots on a
milling machine table where the slot is not open below the T-nut.

"Reentrant" wrote in message
...
The pillar-drill thread finally prompted me to get some T-nuts (the sort
that slide in a slot, not the spiky ones) so I can fix my little
vice/clamp properly to the pillar-drill's table.

I was surprised to find the nuts weren't tapped all the way through. The
supplier said they are all like that, so the bolts have to be exactly the
right length. Is that true? It means the bolts have to be pretty-much
exactly the right length.
--


Well they can't stick out the bottom anyway as they would hit the base of
the T slot.

However I think you want T bolts.
usually they are shaped like a T and you can push them through the top of
the T slot, rotate them about a quarter turn and they stay there while you
put the job and a nut on.

Reentrant

They are deliberately made like that. It's to stop the bolt going
straight through the nut, hitting the bottom of the T-slot and putting
excessive upward load on the slot when it's not supported from above -
believe it or not it's not unknown for a heavy-handed soul to break a
piece out of the T-slot.

As others have said, you use them with a bit of studding screwed in as
far as it will go then a nut and washer on top - that way you can't
damage the T-slot.



On 26/07/2011 14:52, dennis@home wrote:


"Reentrant" wrote in message
...
The pillar-drill thread finally prompted me to get some T-nuts (the
sort that slide in a slot, not the spiky ones) so I can fix my little
vice/clamp properly to the pillar-drill's table.

I was surprised to find the nuts weren't tapped all the way through.
The supplier said they are all like that, so the bolts have to be
exactly the right length. Is that true? It means the bolts have to be
pretty-much exactly the right length.
--


Well they can't stick out the bottom anyway as they would hit the base
of the T slot.

However I think you want T bolts.
usually they are shaped like a T and you can push them through the top
of the T slot, rotate them about a quarter turn and they stay there
while you put the job and a nut on.

Reentrant

On 26/07/2011 14:52, pcb1962 wrote:
On Jul 26, 2:33 pm, wrote:

I was surprised to find the nuts weren't tapped all the way through. The
supplier said they are all like that, so the bolts have to be exactly
the right length. Is that true? It means the bolts have to be
pretty-much exactly the right length.

You're not supposed to use a bolt, you use a stud with a nut and
washer on top.
Nothing to stop you tapping them all the way through. The reason
they're made that way is so that you don't distort the slots on a
milling machine table where the slot is not open below the T-nut.


Thanks all. I saw T-bolts but thought that would leave the threaded-end
sticking up into the work area unless they too were just the right length.

For this application there is no bottom to the slot so nuts work better.
Anyway, problem solved as I shortened the bolts I had - with an angle
grinder.

--
Reentrant