Specifying sharp threads on drawing
Close
Login to Your Account
Results 1 to 13 of 13
  1. #1
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    15
    Post Thanks / Like
    Likes (Given)
    11
    Likes (Received)
    2

    Default Specifying sharp threads on drawing

    So I am considering the possibility of having an evenly spaced round blade made, so if it dulls we can rotate it a few degrees. I was thinking our machine shop might be able to just turn a threaded rod on their lathe at the required TPI, and we could mount the threaded rod on an angle to cut what we need. Is there a good way to specify on the drawing that we need the threads to be as sharp as possible? Thanks!

  2. #2
    Join Date
    Dec 2015
    Country
    UNITED STATES
    State/Province
    Illinois
    Posts
    381
    Post Thanks / Like
    Likes (Given)
    121
    Likes (Received)
    210

    Default

    I think you would be best off speaking directly to your machine shop and explaining what you want. From the outside with little information I'm curious what you are cutting and if you would need to make your "thread" out of something hard enough that grinding would make more since.

  3. Likes AHUNT, Winterfalke liked this post
  4. #3
    Join Date
    Sep 2007
    Country
    UNITED STATES
    State/Province
    Washington
    Posts
    5,094
    Post Thanks / Like
    Likes (Given)
    171
    Likes (Received)
    1439

    Default

    This made sense to me:

    sharp-threads.jpg

    Regards.

    Mike

  5. Likes Oldwrench, AHUNT liked this post
  6. #4
    Join Date
    Jul 2006
    Country
    UNITED STATES
    State/Province
    Arizona
    Posts
    4,507
    Post Thanks / Like
    Likes (Given)
    18199
    Likes (Received)
    4229

    Default

    Quote Originally Posted by AHUNT View Post
    I was thinking our machine shop might be able to just turn a threaded rod on their lathe at the required TPI, and we could mount the threaded rod on an angle to cut what we need.
    The threaded rod will act like an auger if it will be spinning and not do what you want it to do.

    Instead specify a series of grooves with sharp tips.

  7. #5
    Join Date
    Sep 2010
    Location
    Oklahoma City, OK
    Posts
    4,030
    Post Thanks / Like
    Likes (Given)
    706
    Likes (Received)
    1725

    Default

    Quote Originally Posted by Philabuster View Post
    The threaded rod will act like an auger if it will be spinning and not do what you want it to do.

    Instead specify a series of grooves with sharp tips.
    If he angles it right wouldn't it cut straight, like a hob?

  8. #6
    Join Date
    Jan 2007
    Location
    Flushing/Flint, Michigan
    Posts
    7,428
    Post Thanks / Like
    Likes (Given)
    366
    Likes (Received)
    6218

    Default

    Are you trying to make a forming tool or a cutting tool?

  9. #7
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    15
    Post Thanks / Like
    Likes (Given)
    11
    Likes (Received)
    2

    Default

    We were going to lock the rotation of it. We would want to be able to unlock it rotate it a few degrees and relock it.

  10. #8
    Join Date
    Mar 2019
    Country
    UNITED STATES
    State/Province
    New York
    Posts
    15
    Post Thanks / Like
    Likes (Given)
    11
    Likes (Received)
    2

    Default

    Quote Originally Posted by CarbideBob View Post
    Are you trying to make a forming tool or a cutting tool?
    We are making a cutting tool.

  11. #9
    Join Date
    Jan 2007
    Location
    Flushing/Flint, Michigan
    Posts
    7,428
    Post Thanks / Like
    Likes (Given)
    366
    Likes (Received)
    6218

    Default

    Quote Originally Posted by AHUNT View Post
    We are making a cutting tool.
    With that I'm confused as to where the chip formation and shear occurs.
    I get it as metal spinning or forming tool. I don't get the cutting action.
    I'm missing something as to how this works. Is it sort of used like a broach?
    Bob

  12. #10
    Join Date
    Dec 2015
    Country
    UNITED STATES
    State/Province
    Illinois
    Posts
    381
    Post Thanks / Like
    Likes (Given)
    121
    Likes (Received)
    210

    Default

    I'm imagining it slicing like a knife, like when you try to turn a piece of brass all-thread by hand and get a line of cuts instead .

  13. Likes Winterfalke liked this post
  14. #11
    Join Date
    Jan 2007
    Location
    Norfolk, UK
    Posts
    18,369
    Post Thanks / Like
    Likes (Given)
    13910
    Likes (Received)
    13880

    Default

    Quote Originally Posted by Cole2534 View Post
    If he angles it right wouldn't it cut straight, like a hob?
    Due to the helix angle ;- Not unless whatever he's cutting (like a gear) rotates in sync, with the cutter

  15. #12
    Join Date
    Jan 2007
    Location
    Flushing/Flint, Michigan
    Posts
    7,428
    Post Thanks / Like
    Likes (Given)
    366
    Likes (Received)
    6218

    Default

    He wants to rotate it a few degrees when dull for a new edge.

  16. #13
    Join Date
    Nov 2010
    Country
    UNITED KINGDOM
    Posts
    976
    Post Thanks / Like
    Likes (Given)
    193
    Likes (Received)
    236

    Default

    Are you cutting, paper, card, foil, plastic sheet, leather or what?

    How many TPI?
    How long is the threaded bar?
    What diameter?
    Does it have to be Sliver Steel/ Drill Rod so it can be hardened?
    Is depth of cut normal thread depth?
    How is the material being cut moved across the threads?
    Thickness of material being cut?

    Trying to visualise just what is happening.

  17. Likes Limy Sami liked this post

Tags for this Thread

Bookmarks

Posting Permissions

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