Tools for thread cutting

[Rowan Sylvester-Bradley]

If I want to be able to cut a range of smallish (say up to 1/2") threads from metric to UNF/UNC to BSW/BSF/BSP, internal and external, what is the most economical range of tools to buy?

Thank you - Rowan

 

[Dee J]

Tbh, anything smaller than 3/8 I'd do with cheap taps and dies rather than lathe tooling, probably up to 1/2 inch. Larger stuff I grind whatever tool steel I've got to the right angle for the job in question. Mostly done this for random vintage machinery with less common threads.

 

[addjunkie]

I grind my own for most stuff when machining from tool steel, find the inserts a bit large for smaller internal screw cutting.
Taps and dies work fine up to 1/2 inch.

 

[Misterg]

If I want to be able to cut a range of smallish (say up to 1/2") threads from metric to UNF/UNC to BSW/BSF/BSP, internal and external, what is the most economical range of tools to buy?

Thank you - Rowan

You need separate internal and external tools in each of the thread angles you want to cut (60° and 55° typically).

It's pretty easy to grind external tools from HSS, but making internal ones is a pain. HSS internal tools are pretty cheap (£5 - £7 each) - ebay if you can't find them anywhere else. (Warco, Chronos, etc.)

To be honest, it's hard to beat one of the Chinese sets on Amazon if you want insert tooling, but you'd have to check whether both 55° and 60° inserts are available.

Something like this:

https://www.amazon.co.uk/Woodturning-Accessories-Cutting-Turning-Semi-Finishing/dp/B099RPKNP5/ref=sr_1_9?th=1