Rethread discovery tube

[Prouzy]

I need to rethread a Discovery tube, 13/16 28 is the measure from my understanding.  Looking for some input on 1) will a HSS tap do the job or do I need to go to another material, eg carbide, and 2) can I do this adequately by hand? I have not done this on a tube, though I have done this (tap) before and several other projects, and prefer to do it on my own for the experience but can bring to my machinist neighbor if not feasible for me to perform.  I'm also looking for recommendation to get this size tap in the material I need?  Thanks!  Chris

[Rob M]

HSS will be fine , if your neightbor is a machinist, you don't really need the tap ( assuming his lathe will thread 28 tpi )
The taps that size can be found cheap on occasion though , use lube and make sure to clean and remove all that lube after


https://www.ebay.com/itm/13-16-28-HSS-Plug-Hand-Tap/351521118566?hash=item51d84a9966:g:qcAAAOSw9GhYgTQH


you could get one from china for 13 bux , but that's 3 weeks waiting .

[Rob M]

amazon link to the same




AND HERES CHINA FOR 13

https://www.ebay.com/itm/S-1pcs-13-16-28UN-HSS-TAP-Right-helix-Inch-MACHINE-TAP-13-16-28-US-TAP/291849189090?hash=item43f39136e2:g:nNoAAOSwU-pXtR-Q

[Prouzy]

Awesome, thank you Rob! I ordered one and will give it a try on some cut offs.  If it does not go well, I will meander over to the neighbors shop  . Thanks!