Drill size for 1/8-27 pipe tap?

snapperbait

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Fellers.... <br /><br />Anyone know the proper size drill bit for a 1/8"-27 thread pipe tap?..<br /><br />Love my Craftsman tap and die set, but unfortunately Craftsman neglected to include the drill size info for that tap...<br /> :confused:
 

ob

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Re: Drill size for 1/8-27 pipe tap?

I'll second the letter drill "R" for 1/8" /27 NPT.
 

rodbolt

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Re: Drill size for 1/8-27 pipe tap?

yep :) <br /> glad me an OB jot the same tap chart on the favorites :)
 

ob

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Re: Drill size for 1/8-27 pipe tap?

Originally posted by rodbolt:<br /> yep :) <br /> glad me an OB jot the same tap chart on the favorites :)
Had a nice card I carried for years in my wallet but it's getting hard to read. :)
 

Paul Moir

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Re: Drill size for 1/8-27 pipe tap?

Sounds like you folks are quoting from the NPTF (Dry Seal) column not the NPT column. :) But I really think we're splitting hairs since it's really gonna depend on how much he runs that tap in.<br />Dammit, is it just me, Starrett and my Busy Bee Tools poster that agree on that? :D
 

ob

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Re: Drill size for 1/8-27 pipe tap?

Several charts I have refered to list the letter drill R for 1/8" 27 National tapered pipe thread.I found one that listed the letter drill Q. :confused: I agree , between the two sizes is splitting hairs when it comes to decimal size and the criticality of tapping a hole to recieve a 1/8" NPT nipple.
 

RPJS

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Re: Drill size for 1/8-27 pipe tap?

This is a little off topic but I've always wondered why the world cannot agree on one standard for threads & bolt sizes.<br /><br />Or should that read why can't the US use the same standard as the rest of the world.<br /><br /> ;) :confused: ;)
 

rodbolt

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Re: Drill size for 1/8-27 pipe tap?

we do<br /> now where are my whitworth wrenches?<br /> tell ya what, when the brits make Lucas systems that work we will allow ya to use our tool sizes :)
 

ob

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Re: Drill size for 1/8-27 pipe tap?

We was wondering why the rest of the world doesn't use our national standard. :) <br /><br />Actually the USA now incorporates all standards of thread sizes and has for years.Just that our original national standards are still one of the standards.Sorta like gallons and litres.Or is that liters? :D <br /><br />Besides ,metric bolts in my Evinrude just wouldn't be right. :cool:
 

rodbolt

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Re: Drill size for 1/8-27 pipe tap?

but the brits have a pipe size as well :) <br /> it also depends on the materiel to be tapped and whether or not its a tapered,sealing, or straight,non-sealing pipe joint. <br /> the shift cable in the merc bell housings are modified from fwd entry to aft entry with a 1/4-14 straight NPT. I also use it to chase the threads after I have to drill out the snapped off cable.<br /> there is a book about 200 pages long describing thread sizes and standards, I machined class 3 threads for mny years as well as metric,buttress,acme,stub acme, pipe and a host of other oddball stuff.
 

Bondo

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Re: Drill size for 1/8-27 pipe tap?

when the brits make Lucas systems that work we will allow ya to use our tool sizes
Ayuh,........ Lucas,... John Lucas,... Prince of Darkness................ :D ;) <br /><br />Lucas Electrics Alway Work,..............Til ya Need it.........
 
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