Round or Hex dies

[Displaced Canadian]

I was looking for a die holder for my lathe yesterday and could only find one for round dies. After more reading I find people saying that round dies are for cutting new threads and the hexagon ones are for repairing threads. Is this true? Presently the hex ones I have work fine so I'll continue to use them. Anything else I should know about this?

 

[Rich L]

That's generally true, however, I have used many a hex die to cut new threads of the "loose" class of fit even in "grade 8" steel although I try to avoid that. Works fine, generally. You cannot manage class of fit with hex dies, though. The round dies I have cut a lot better.

Cheers,
Rich

 

[Displaced Canadian]

Are the adjustable ones worth getting?

 

[Andrew_K99]

Here is a thread skiprat wrote a few years ago on threading, he discusses dies on the 4th page. http://www.penturners.org/forum/f30/dummies-guide-tapping-lathe-59693/

AK