In article ,
Tim Wescott wrote:

On Tue, 29 Dec 2009 16:06:57 -0800, Roger Shoaf wrote:

"David Billington" wrote in message
...

Maybe try and determine what T slot standard your lathe uses, you may
be able to buy the T nuts more cheaply and they will likely be case
hardened. I had a look at this recently as I made a T slot table for
the cross slide of my Harrison M300 and looked at the various T slot
sizes I had, the BP set was predominant but the size used on a 10"
Vertex rotary table won out at 7/16" T slot as far as I could tell.
IIRC there are old and new ISO standards with differing dimensions and
the inch size T slot standard. For the Vertex table that I have I made
T nuts to suit the slots and to suit the 1/2" Whitworth clamping kit
even though the T slots appear to be 7/16" spec.

I agree Enco sells Tee nuts down to 1/4 20 already heat treated.

But I've tried that, and gotten tee nuts that don't fit.

My table has a T-slot that matches what Enco sells except for the height
of the 'top' bar of the T, which must be ground down:

.---.
| |
.---' '---. ------
| | this height is too big
'-----------' ------

And I can't see where they have dimensioned drawings of their tee nuts
(nor, for that matter, does a search on 'tee nut' get me a nut to fit in
a T slot).

It would be nice to get the right thing.

I've had that problem matching new T-nuts or T-bolts to older equipment,
but it's easy to fix. The T hardware is hardened, but for toughness,
not hardness, and an end mill has no problem cutting this hardware to
size. HSS mills work, and of course carbide really works.

But before doing that I would try metric T-Nuts and T-Bolts, as I bet
that the Smithy is made in China.

Nor is it particularly hard to make a custom T-Nut.

Joe Gwinn