Thread dies, question.

[J-G]

Tracey tools are a good source of good quality taps and dies at fair prices.
And always buy HSS at least,

I'll second both of those statements!

...the ones in most cheap kits are too soft to cut or last well, and tend not to be very accurate either.

Cheap kits will pretty certainly be Carbon Steel rather than HSS. These will not necessarily be 'soft' but will lose their edge sooner depending upon the material that you are cutting. Used on Brass or Industrial plastics - or even to clean up existing threads - they should give reasonable service. I do have some Carbon Steel dies but only in the BA Thread series and use these to cut Brass rather than Steel.

 

[Duncan A]

If you do not have cutting fluid, use grease, not oil.
Best - cutting fluid
OK - grease
Poor - oil
Duncan

 

[pe2dave]

Another thumbs up for Tracy tools. Wide ranging stock and helpful.

 

[Ttrees]

Thanks for your suggestions again folks.
Had another shot for the craic, and the tap at least seemed to engage.
Had to press on the tap itself, as the wrench provided wasn't gripping the cutter flush.
This was why it wasn't engaging on the work, as my wee ball vice wasn't able to grip the rod.
No ability to rotate my new vice vertically,
If I really needed I could have rigged up the vice to a leg of the bench.
That'll be necessary if needing to use these thread dies, should I have another shot.

I can't fault these yet, as the stock is definitely undersized
9.2 mm at it's maximum, for a m10 thread isn't gonna cut the mustard.
I thought I'd be able to get some sort of thread all the same though,
as I've used these on old soft nails to make wee bolts, and they didn't appear to loose anything off the diameter,
It appeared to burnish the threads and possibly increase diameter, but admit I never checked.

Be interesting to see if a good tap would make more pronounced sharper threads,
as you can see there's no slit in the cutter,
and made sure the tool was the right orientation, just incase I had it wrong.

Also got some grease, although likely not what one would use for tapping.
Might have improved things.

Although no backing out and breaking the chip was necessary, as there was little resistance.


Pretty lousy result, don't have any 10mm round stock to try, but I think I would expect better results
with that, from what you folks are saying.

Sorry can't give a review of these, nor an answer for those who might have been curious.
The only rods in the shed I have are already threaded.

Thanks again folks
Tom

 

[J-G]

That Die-Stock is suitable for use with 'Adjustable' -- ie. split -- dies and you could turn that M10 die into a split die as well. If you have access to a Dremel with a slitting disc you could cut through where the 'V' is.

Starting with 9.2mm dia stock though will always be a problem and of course you don't know what grade of steel it is. It could well be 'black bar' or En32 neither of which will yield a 'clean' thread.

 

[jimmy_s]

"The stock should be 10mm diameter or slightly over for M10."
Wrong!!! It should be slightly UNDER for a good finish. The threads are slightly rounded, so with an M10 thread you get an outer diameter of from 9.85 to 9.95 mm. If the stock is thicker it's harder to thread, and also, you're likely to get tearing. Looking at the image you can see why the threaded part is slightly under the nominal diameter. That's also why when cutting threads with a lathe, you square off the tips of the threads slightly.
View attachment 118349

He's not cutting it on a lathe he's cutting it with a die stock. Personally I open the die up slightly and cut it oversize and then drop the die back on grubscrews and fit the other thread. Get a better finish IMO but I'm sure there's more than one way to do it.

 

[cowtown_eric]

hexagonal dies are intended for rethreading, or thread restoration. Round dies are for cutting new threads. Found that out about a year ago.

Eric in the colonies

 

[Inspector]

Ah Eric there are exceptions to those rules. I have a HSS tap and die set I bought from the Mac tool truck 40 odd years ago that has hex dies and taps from #4 to 1/2" coarse and fine that were sold for cutting threads which they do nicely. Okay unknown stainless rod not so much. The dies are not split like the decent round dies usually are but they still cut. I see no reason a set would have taps for thread cutting, (marked with the tap drill size) and dies for thread chasing in the same box.

I also have thread restoration dies (thread chasers) that would have a hard time cutting a thread in liquorice, red or black. They are nut sized so you can run them down the bolt with the same wrenches you use for the nuts of that thread size.

There is a definite difference in the two.

I see the OP problem as being the undersized mystery metal.

Pete