On 2010-12-07, David Billington wrote:
DoN. Nichols wrote:
On 2010-12-06, Searcher7 wrote:

Can I get recommendations of which and how many screw thread
gauges(gages?) one should own to cover the most common threads one is
likely to run into? (Including metric, but I live in the U.S.).

[ ... ]

Two -- one metric, and one inch. There are inch ones available
(mine is from Starrett) which have three groups of gauge leaves, and if
that doesn't cover what you need, it will probably be a coarse enough
thread to measure by a steel ruler -- and too coarse to cut on a home
lathe.

[ ... ]

You could add the No. 155, which covers from 28 TPI up to 2.25
TPI -- but -- why would you need to measure one that coarse, since you
can't cut it at home anyway.


My Harrison M300 does 2TPI as standard and it has been needed on one
occasion when my neighbour needed to cut an internal twin start square
thread for the nut on his dining room table jack as it had finally wore
out after about 200 years. He couldn't do it as his Myford Super 7
doesn't go that coarse so he came around and did it at my house.

And how big is the Harrison M300? The original poster has to
live with machines which he can take upstairs to his apartment -- by
himself. My 12x24" Clausing can only manage 4 TPI maximum coarseness,
and there is no way he would be able to get it up to his apartment.

And the thread pitch gauges which he is considering would not
work for your square threads anyway. But the steel ruler which I
mentioned above in my first still quoted paragraph *would* do just fine
for determining the pitch of the 2 TPI thread.

Enjoy,
DoN.

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