Page 2 of 2 FirstFirst 12
  1. #11
    I simply drill a hole in some MDF about the size of the cutter dia. Harden it with CA glue and finish bore it with the tool. Then measure the hole carefully. This gives me my offset.

  2. #12
    Should have said to be careful with various tool tip radii. These will of course vary the cutting dia and thus the depth of the form when trying to match an existing thread. Imagine a huge tip radius verses a tiny one. The V form would cut in different places. Start small and creep up on it.
    Last edited by Leadhead; 5 Days Ago at 03:08 PM.

  3. #13
    Best if you download and look at the little app that Richard has on the Chestnut Pens website - that defines the dimensions that you need. I measured mine by clamping the tool in a vee block and careful use of a digital height gauge, it was very quick. The app is designed for metric threads so it calculates dimensions from the standard formulas - it would presumably work for UNF, but I don't think it would for imperial 55 degree forms.

  4. #14
    One of the benefits of using a TCT threading tool or a tap is that it already includes the flat or radius. I just used the app, chose my fit class, and it worked.

  5. #15
    John - My caution above is born of trying to use standard 55 deg trapezoidal tips which do not always, of course, have a compatible tip radius. Tripped me up until the penny dropped, but close approximations can be found if you search. I have tried it on the CA hardened MDF only so far. But reproduced a heavy Whit. thread quite well,

Page 2 of 2 FirstFirst 12

Similar Threads

  1. Thread milling
    By Leadhead in forum Tool & Tooling Technology
    Replies: 1
    Last Post: 09-02-2018, 09:23 AM
  2. Milling Plastazote LD33 closed cell Foam - Any milling advice?
    By Zeeflyboy in forum General Discussion
    Replies: 11
    Last Post: 20-11-2017, 12:46 PM
  3. Square/Acme/Trapezoidal thread milling?
    By m_c in forum Tool & Tooling Technology
    Replies: 4
    Last Post: 22-04-2017, 11:07 AM
  4. inspiration thread
    By kingcreaky in forum General Discussion
    Replies: 47
    Last Post: 21-01-2016, 02:08 PM
  5. Thread milling shallow bind hole
    By suesi34e in forum Metalwork Discussion
    Replies: 28
    Last Post: 15-12-2015, 12:03 PM


Posting Permissions

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