In article

,
Ivan Vegvary wrote:

Installing an old mortise lockset into a front door. Lockset was purchased
(quite pricey with door knobs, cover plates etc.) from a restoration hardware
place. They reconditioned all the parts and patinated (sp?) them all to look
similar.

Problem: The threaded lock cylinder needs to be fixed from rotation with a
radially applied screw that is over 2-1/4 inches long. The existing threads
in the bronze casing is 8-32. I have three choices:
1) Find a screw of the proper length and 8-36 thread with a fillister head
2) Find any long 8-36 screw and turn down the head to fit the hole
3) Re-tap the threads for 8-32 which opens a whole world of screws.

The problem with option 3 is that all of my 8-32 taps (I have over 50) are
about a 1/4 to a 1/2 inch too short. Have any of you successfully lengthened
an existing tap? I have mig, tig & oxy but am worried about axial alignment
on the tap extension.

What are the probable result of re-tapping an 8-36 to an 8-32 in bronze?
Will I end up with a crappy loose thread fit?

BTW, tried McMaster-Carr and Fastenall. At McMaster I cannot find 8-36. At
Fastenall, I do find 8-36 but maximum length is 1-1/4 inches. I would need
to buy quantity 100 but at least I would get to practice my screw-lengthening
skills which should be easier than tap-lengthening.

All advice appreciated.

Ask around (with the name of the lockset manufacturer in hand) at the
local locksmiths. The old ones are often packrats.

If local doesn't do it, ask at "alt.locksmithing".

Joe Gwinn