Cutting a male thread

[John Bateson]

I have some NiSi rod 1.6 mm dia. and I want to cut a thread on the end of it.
Do I just use the 1.6mm die in the box or is there some sort of conversion chart for different diameter rods?
I guess to get it started I just file the end down ...
John

[grovenor-2685]

Yes the size should be the outside diameter of the thread, there should be no need for a taper on the work, just deburr it. The die should be tapered internally and should start just fine, you need to sight the dieholder nicely at 90 degrees to the workpiece so it starts correctly.
Regards
Keith

[Alan Turner]

Make sure you lubricate the cut, preferably with proper thread cutting paste but at the very least spit on it!

Don't forget to turn in quarter turns, backing off after each cut.

Alan

[Terry Bendall]

Do I just use the 1.6mm die in the box

For an external thread the size of the bar is always the size of the thred.

The die should be tapered internally and should start just fine

Yes it should, and normally on the side where the size is given. Sometimes a bit of rounding off, i.e. a bit more than just deburring is useful.

you need to sight the dieholder nicely at 90 degrees to the workpiece so it starts correctly.

A way of getting the die to start square is shown on page 6 of Scalefour News 158

Make sure you lubricate the cut, preferably with proper thread cutting paste

In the absence of paste, soluble oil will do the job well, or even lubricating oil, but you only need this on steel. No lubrication is needed on brass or nickel silver.

Terry Bendall

[grovenor-2685]

A way of getting the die to start square is shown on page 6 of Scalefour News 158

Not in my copy Terry?
Regards
Keith

[John Bateson]

Thank you for all the replies - very useful.
John

[Terry Bendall]

Not in my copy Terry?

Sorry - it is in 160. In that issue someone made a mistake with the issue number at the top of each page which is given as 159 so I was wrong anyway.

Terry Bendall

[John Bateson]

Incorrect labelling?
and I wonder who that could be ...
Perhaps the editor was under the weather and had submitted to an application of the Macallan after seeing the front page contribution.