Please note this thread has been inactive for 90 days. For the best results, please start a new thread.
Results 1 to 15 of 15
  1. #1
    Vice Admiral snapperbait's Avatar
    Join Date
    Aug 2002
    Posts
    5,762

    Default Drill size for 1/8-27 pipe tap?

    Fellers.... Anyone know the proper size drill bit for a 1/8"-27 thread pipe tap?..Love my Craftsman tap and die set, but unfortunately Craftsman neglected to include the drill size info for that tap...
    I don't give interviews, and I'm no longer a public figure..

  2. #2
    Admiral
    Join Date
    Aug 2002
    Location
    corpus christi texas
    Posts
    6,873

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


  3. #3
    Admiral
    Join Date
    Nov 2002
    Location
    Nova Scotia
    Posts
    6,839

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

    Letter Drill Q = .332I guess 21/64 or 11/32. Probably 21/64 since it's a tapered tap anyway.Excellent resource: http://catalog.starrett.com/catalog/...30801&Mode=REF I used to have these pinned up all over my shop, but now I've got an even better chart that cross-references them all. EDIT: Slow... so slowww...

  4. #4
    Supreme Mariner
    Join Date
    Sep 2003
    Location
    Kitty Hawk NC
    Posts
    20,072

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

    tap drill size is R. http://www.engineersedge.com/tap_drill_chart.htm and a site with conversions from letter to fractions. http://www.csgnetwork.com/drillsizeconvert.html
    no tech questions by PM, they wont get answered.
    you have to be trusted by the people that you lie to .

  5. #5
    Admiral
    Join Date
    Aug 2002
    Location
    corpus christi texas
    Posts
    6,873

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

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

  6. #6
    Supreme Mariner
    Join Date
    Sep 2003
    Location
    Kitty Hawk NC
    Posts
    20,072

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

    yep glad me an OB jot the same tap chart on the favorites
    no tech questions by PM, they wont get answered.
    you have to be trusted by the people that you lie to .

  7. #7
    Vice Admiral snapperbait's Avatar
    Join Date
    Aug 2002
    Posts
    5,762

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

    I thanks ya'll....
    I don't give interviews, and I'm no longer a public figure..

  8. #8
    Admiral
    Join Date
    Aug 2002
    Location
    corpus christi texas
    Posts
    6,873

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

    Originally posted by rodbolt: yep 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.

  9. #9
    Admiral
    Join Date
    Nov 2002
    Location
    Nova Scotia
    Posts
    6,839

    Default 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.Dammit, is it just me, Starrett and my Busy Bee Tools poster that agree on that?

  10. #10
    Admiral
    Join Date
    Aug 2002
    Location
    corpus christi texas
    Posts
    6,873

    Default 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. 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.

  11. #11
    Lieutenant Commander RPJS's Avatar
    Join Date
    Jul 2002
    Location
    UK
    Posts
    1,574

    Default 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.Or should that read why can't the US use the same standard as the rest of the world.
    MM World match fishing champion 2007/2008

  12. #12
    Supreme Mariner
    Join Date
    Sep 2003
    Location
    Kitty Hawk NC
    Posts
    20,072

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

    we do now where are my whitworth wrenches? tell ya what, when the brits make Lucas systems that work we will allow ya to use our tool sizes
    no tech questions by PM, they wont get answered.
    you have to be trusted by the people that you lie to .

  13. #13
    Admiral
    Join Date
    Aug 2002
    Location
    corpus christi texas
    Posts
    6,873

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

    We was wondering why the rest of the world doesn't use our national standard. 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? Besides ,metric bolts in my Evinrude just wouldn't be right.

  14. #14
    Supreme Mariner
    Join Date
    Sep 2003
    Location
    Kitty Hawk NC
    Posts
    20,072

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

    but the brits have a pipe size as well it also depends on the materiel to be tapped and whether or not its a tapered,sealing, or straight,non-sealing pipe joint. 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. 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.
    no tech questions by PM, they wont get answered.
    you have to be trusted by the people that you lie to .

  15. #15
    Moderator Bondo's Avatar
    Join Date
    Apr 2002
    Location
    The Mouth of the Chaumont River, Ny.
    Posts
    52,607

    Default 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................ Lucas Electrics Alway Work,..............Til ya Need it.........
    Any Grease is Better,..... Than No Grease at All.......

Similar Threads

  1. What size drill bit...
    By tie_one_on in forum Non-Boating Technical Topics
    Replies: 6
    Last Post: March 17th, 2006, 08:46 AM
  2. size drill & tap for hellicoil
    By reeldutch in forum Johnson & Evinrude Outboards
    Replies: 5
    Last Post: February 14th, 2006, 01:22 PM
  3. Water Outlet Drill bit size??
    By Kenny Sorweide in forum Johnson & Evinrude Outboards
    Replies: 19
    Last Post: February 11th, 2005, 07:23 PM
  4. To drill or not to drill? Rod Holders Installation
    By Kesh in forum Boat Topics and Questions (not engine topics)
    Replies: 17
    Last Post: January 28th, 2003, 02:27 AM
  5. JB Weld Cracked Block need drill hole size
    By Starchief64 in forum Non-Repair Outboard Discussions
    Replies: 1
    Last Post: May 17th, 2002, 06:42 AM
  1. iboats Forum Directory - Over 100,000 forum posts organized by topic