Page 1 of 4 123 ... LastLast
Results 1 to 10 of 35

Thread: Okay - when did 1" UNF threads change???

  1. #1
    Join Date
    Apr 2007
    Location
    South Texas
    Posts
    983

    Default Okay - when did 1" UNF threads change???

    I look on all the charts and they all list 1 inch fine threads as 1"-12. So, is ask the boss to get me a couple 1"12 x 4" inch bolts for a project I am finishing and everyone tells us that the thread is 1"-14... So, Just when exactly did this change? and what other changes to the standard have happened?

    I even have the 1"12 tap....

  2. #2
    Join Date
    Dec 2016
    Location
    Helsinki, Finland, Europe
    Posts
    2,357

    Default

    https://en.wikipedia.org/wiki/Unified_Thread_Standard

    "(*) For many years non-standard 1-inch 14-tpi nuts and bolts have been widely used instead of standard-sized 1-inch 12-tpi fasteners; consequently 1″-14 fasteners are easier to find and less expensive than 1″-12 fasteners. After several decades 1″-14 fasteners have now come to be commonly referred to as "Standard Fine Thread" or "UNF". Though technically incorrect (the UNF standard specifies 1″-12), size 1″-14 is universally accepted as standard for fine-threaded 1-inch fasteners, and "1-inch 14-tpi NF" has become established as a "common use" term, or "a genericized brand name/standard". In other words, the 1″-12 standard has lacked effective enforcement for a long enough time (many decades) to give generic trademark–like status to 1-inch 14-tpi fasteners."

    So it's the standard unstandard

  3. #3
    Join Date
    Mar 2005
    Location
    Toronto
    Posts
    10,108

    Default

    Quote Originally Posted by MattiJ View Post
    https://en.wikipedia.org/wiki/Unified_Thread_Standard

    "(*) For many years non-standard 1-inch 14-tpi nuts and bolts have been widely used instead of standard-sized 1-inch 12-tpi fasteners; consequently 1″-14 fasteners are easier to find and less expensive than 1″-12 fasteners. After several decades 1″-14 fasteners have now come to be commonly referred to as "Standard Fine Thread" or "UNF". Though technically incorrect (the UNF standard specifies 1″-12), size 1″-14 is universally accepted as standard for fine-threaded 1-inch fasteners, and "1-inch 14-tpi NF" has become established as a "common use" term, or "a genericized brand name/standard". In other words, the 1″-12 standard has lacked effective enforcement for a long enough time (many decades) to give generic trademark–like status to 1-inch 14-tpi fasteners."

    So it's the standard unstandard
    Timely, was just yesterday working with a 1" 14 and wondering the same thing
    .

  4. #4
    Join Date
    Jan 2003
    Location
    Deep in the Heart of Texas!
    Posts
    7,512

    Default

    I know what they're doing. They're trying to get us use to finer threads so they can slip-in a metric without us knowing.

    I cut my first M10 x 1.0 the other day.

  5. #5
    Join Date
    Apr 2017
    Location
    Kelowna BC
    Posts
    1,273

    Default

    Now you get to make your own bolts, first make studs, then weld or loctite nut on one end.

  6. #6
    Join Date
    Jul 2003
    Posts
    125

    Default

    This on bite me in the butt a while back customer gave me a print with a 1" Fine hole he didn't list the TPI on the print. So I look on the thread chart and it lists 1" 12 as fine so I get the hole taped. He comes by with the bolts for the project and they don't fit there 1"14. luckley I only did the one of 4 of the parts as we only had the metal to do one at that time. 1" 12 is crossed off all my thread charts you can't find 1" 12 bolts in Portland OR. Wwe were going to make all the parts 1"12 but after a few phone calls we scraped the part. Ken

  7. #7
    Join Date
    May 2015
    Location
    Somerset UK
    Posts
    1,619

    Default

    My UNF thread chart lists 1" and everything above as having 12 tpi. At least up to 3" diameter.

  8. #8
    Join Date
    Feb 2005
    Location
    Central Mother Lode. California
    Posts
    44

    Default

    I've never had this come up but I just looked at some of my references. My Starrett wall chart (1999) and my South Bend Lathe wall chart (picked up at IMTS in 1994) show 1"-14 as standard. The South Bend wall chart further shows the 1"-12 as "Special". My _Starrett Book for Student Machinists_, 16 ed., rev. (1975) and my _Machinery's Handbook_ 21st ed., 1979 both list 1"-12 as standard.

    Egad screw threads are fascinating!

    David

  9. #9
    Join Date
    Nov 2002
    Location
    Cheshire, CT
    Posts
    203

    Default

    I just checked on the Mc Master web site. In hex head bolts, they only have 1"-14 NF , but they have both 1"-12 and 1"-14 taps. Go figure!
    Craig

  10. #10
    Join Date
    Dec 2016
    Location
    Helsinki, Finland, Europe
    Posts
    2,357

    Default

    Quote Originally Posted by ckalley View Post
    I just checked on the Mc Master web site. In hex head bolts, they only have 1"-14 NF , but they have both 1"-12 and 1"-14 taps. Go figure!
    Craig
    But nuts are available widely in many variations (grade 5/grade8/nyloc/stainless/another stainless/extreme) also in 12 TPI !

    No bolts of any kind but plenty of nuts. Thats NUTS!

    Doesn't make sense (no supprise here, I have given up on threaded parts)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •