I'm new to machining & tools.

I have a myford lathe that I bought a couple of yrs ago
and I've been playing occasionally.
I now need to make a 'real' part to fix the mower.
Basically a rod with threads on each end, one is a LH thread.
Yep I could buy a new part, but that would be to easy!

So I went to local tool store, who didn't have much of anything
let alone things I thought I wanted ( I thought I wanted some of those
carbide tipped tools). But I did buy 2 x M42 1/4 x 2.5" 8% cobalt
toolbits which where the only toolbits they had (OK not much of a tool
shop I know, but it was sat morning & it was best I could find.)

To cut my thread I know I need to make a 60deg tool.
But these toolbits I bought seem to good & sharp for me to start
grinding them!

So before I do, I'm wondering, are they designed & made to be used "as
is"? Should I be making my 60deg tool out of some HSS I got with the 2nd
hand lathe? or should I just buy some of those carbide replacement tip
tools from ebay & save the M42's for something else later on?

Thanks for any help getting a begineer started.