I need to add some 1/4-20 threaded, blind holes to a 4" thick granite
surface plate, and I found a diamond core drill that will make the
holes. What is the best type of thread insert to use for this application?

If I were doing that, I think I would use Keenserts. That is a insert
that is theaded on the OD. Looking in J & L they sell a similar insert
called Re-Nu.
The OD is 7/16-14. Should lock in well with epoxy. If you ever need
to replace them, you could drill them out and glue in a new insert.

Dan

"Tim Killian" wrote: (clip) What is the best type of thread insert to use
for this application?
^^^^^^^^^^^^^^
I'm not saying this is best, but I want to be sure a good possibility is not
overlooked. Lok-tite and Permatex both make epoxy products that are
intended for repairing stripped threads. You apply a release agent to the
screw, gob on the epoxy, and insert the screw in the hole. In five minutes
the screw can be removed, and you have a threaded hole.

Do the holes have to be blind? Drill all the way through and put flanged
inserts in if you can.
(top posted the right way)

"Tim Killian" wrote in message
...
I need to add some 1/4-20 threaded, blind holes to a 4" thick granite
surface plate, and I found a diamond core drill that will make the holes.
What is the best type of thread insert to use for this application?

Thanks to all for the suggestions. The surface plate is 4" thick, and I
need to put in 12 holes, so going all the way through with a bit less
than 1/2" diameter is not too appealing ;-)

We use helicoils all the time and I'm familiar with that type of insert.
I was hoping someone made a high quality expanding insert with hardened
internal threads specifically for use in stone materials. The galvanized
stuff they sell at HD is really intended for one use only.

Maybe the best solution is a helicoil insert epoxied into the plate.

Tom Gardner wrote:

Do the holes have to be blind? Drill all the way through and put flanged
inserts in if you can.
(top posted the right way)

"Tim Killian" wrote in message
...

I need to add some 1/4-20 threaded, blind holes to a 4" thick granite
surface plate, and I found a diamond core drill that will make the holes.
What is the best type of thread insert to use for this application?

On Fri, 25 Mar 2005 10:10:10 -0700, Tim Killian



Greetings Tim,
The inserts I've seen were all glued in. Having an insert expanded
into the granite might be a bad thing. Really, a surface plate needs
to be stress free to maintain it's really flat surface. The Keenserts
that were mentioned are made to be used with regular taps. They are
solid with threads on the outside as well as the inside. They are
available in many different alloys. If epoxy doesn't thrill you there
is another solution. It's an adhesive called ROCKSETT. Flexbar sells
it. It would work very well for your situation.
http://flexbar.com/Merchant2/merchan...uct_Code=15014
The above link will get you to a place that sells it. I believe
Flexbar also sells the threaded inserts.
Cheers,
Eric

wrote:

Thanks to all for the suggestions. The surface plate is 4" thick, and I
need to put in 12 holes, so going all the way through with a bit less
than 1/2" diameter is not too appealing ;-)

We use helicoils all the time and I'm familiar with that type of insert.
I was hoping someone made a high quality expanding insert with hardened
internal threads specifically for use in stone materials. The galvanized
stuff they sell at HD is really intended for one use only.

Maybe the best solution is a helicoil insert epoxied into the plate.

Tom Gardner wrote:

Do the holes have to be blind? Drill all the way through and put flanged
inserts in if you can.
(top posted the right way)

"Tim Killian" wrote in message
...

I need to add some 1/4-20 threaded, blind holes to a 4" thick granite
surface plate, and I found a diamond core drill that will make the holes.
What is the best type of thread insert to use for this application?

http://www.rockofages.com/precision/oem.html

Try the above company. We buy from them and specify inserts. If you query
them they may tell you what you need to know and what or how they install
inserts.
lg
no neat sig line

"Tim Killian" wrote in message
...
I need to add some 1/4-20 threaded, blind holes to a 4" thick granite
surface plate, and I found a diamond core drill that will make the holes.
What is the best type of thread insert to use for this application?

On Fri, 25 Mar 2005 10:10:10 -0700, Tim Killian



Greetings Tim,
The inserts I've seen were all glued in. Having an insert expanded
into the granite might be a bad thing. Really, a surface plate needs
to be stress free to maintain it's really flat surface. The Keenserts
that were mentioned are made to be used with regular taps. They are
solid with threads on the outside as well as the inside. They are
available in many different alloys. If epoxy doesn't thrill you there
is another solution. It's an adhesive called ROCKSETT. Flexbar sells
it. It would work very well for your situation.
http://flexbar.com/Merchant2/merchan...uct_Code=15014
The above link will get you to a place that sells it. I believe
Flexbar also sells the threaded inserts.
Cheers,
Eric

wrote:

Thanks to all for the suggestions. The surface plate is 4" thick, and I
need to put in 12 holes, so going all the way through with a bit less
than 1/2" diameter is not too appealing ;-)

We use helicoils all the time and I'm familiar with that type of insert.
I was hoping someone made a high quality expanding insert with hardened
internal threads specifically for use in stone materials. The galvanized
stuff they sell at HD is really intended for one use only.

Maybe the best solution is a helicoil insert epoxied into the plate.

Tom Gardner wrote:

Do the holes have to be blind? Drill all the way through and put flanged
inserts in if you can.
(top posted the right way)

"Tim Killian" wrote in message
...

I need to add some 1/4-20 threaded, blind holes to a 4" thick granite
surface plate, and I found a diamond core drill that will make the holes.
What is the best type of thread insert to use for this application?

Thanks for the link -- I'll check them out next week.

larry g wrote:

http://www.rockofages.com/precision/oem.html

Try the above company. We buy from them and specify inserts. If you query
them they may tell you what you need to know and what or how they install
inserts.
lg
no neat sig line

"Tim Killian" wrote in message
...

I need to add some 1/4-20 threaded, blind holes to a 4" thick granite
surface plate, and I found a diamond core drill that will make the holes.
What is the best type of thread insert to use for this application?

I would not use a helicoil. Youl milage may vary from mine, but if I
tried epoxiing in a helicoil, I would end up with epoxy on the inside.
There are a lot of threaded inserts intended to be used in concrete.
Some expand into place. I think others have lead around the insert and
you mash the lead with a tube so it expands to grip the concrete and
the insert. Try looking at Fastenal or Grainger.

Dan

Here is a traditional concrete anchor designed to provide a
threaded hole.

http://www.interstate-screw.com/tampin/tampin.html

(top posted for your convenience)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Keep the whole world singing . . . .
DanG (remove the sevens)




"Tim Killian" wrote in message
...
I need to add some 1/4-20 threaded, blind holes to a 4" thick
granite surface plate, and I found a diamond core drill that will
make the holes. What is the best type of thread insert to use for
this application?