In article ,
Grant Erwin wrote:

I'm making up a weldment in which the design calls for a continuous 2" of
internal threading. About 3/4" of it will be a threaded hole, and the rest
will
be part of a rod coupler nut. I don't want the threads to bind. What I'm
thinking is to drill the 3/4" deep hole as though I were going to tap it, then
make up a scrap screw with the end 3/4" turned down to be a slip fit into the
tap hole, then use the scrap screw as an alignment tool to hold the coupler
nut
centrally, clamp it tightly, weld it up, then remove the part to the hand
tapper
and chase the threads in the coupler nut and use those to guide the tap to cut
the threads below.

I would just drill and tap the 3/4" hole and run my scrap screw in and screw
on
the coupler nut, clamp it and weld it, but I've seen enough pieces move "just
a
little" when welding to be leery. I don't want these threads to bind.

The threads are 5/8-11 so if they do bind, it could be really difficult to
fix.

Ideas?

GWE

How about using a piece of internally threaded tubing the entire
required length, then sink a hole into the material large enough to
accept the tube and 3/4" deep, and weld the tube in place? Might be
easier to make and guarANTEES GOOD THREADS. SORRY, I HIT MY CAPS LOCK
KEY AND THE FRIGGIN' THING IS STUCK NOW. DAMNIT!

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