[Jewelry making - Article 00300] - Re: [Orchid] Tapping earring post

[Jeff Simkins]

========[ Invite a Friend - http://www.ganoksin.com/invite.htm  ]========

Phillip,

    When creating a loose thread from tapping use a larger drill bit. 

    From Morse Cutting Tool's "Machinist's Practical Guide": 

    Example: screw size #0-80
    Body drill: 52

    Size or number of drill for percent of full thread
    100% tap drill: 58
    80% tap drill: 57
    75% tap drill: 56
    70% tap drill: 56
    60% tap drill: 3/64"
    50% tap drill: 3/64"

    Interesting notes: 

    "A 53% thread will break the bolt, before it will strip - in most
    cases." 

    "A 100% thread is only 5% stronger than a 75% thread, but it requires
    three times the power to tap." 

    Most of the work I do (steel, ss, polymer, aluminum prototyping) is
    cut at 75% full thread. I might index one drill bit size larger than
    recommended if I'm in a hurry on non-critical stuff. 

    Off list I can give you the drill bit numbers for the taps you are
    working with. For very thin stock, you will want to use 100% full
    thread, whereas the above is for holes as deep as the diameter of the
    tap. 

Jeff Simkins
http://blackicepond.deviantart.com
____________________________________________________________________
T h e   O r c h i d   L i s t
Open Electronic Forum for Jewelry Manufacturing Methods and Procedures
____________________________________________________________________
Orchid FAQ:
~ http://www.ganoksin.com/orchid/faq.htm
Orchid Archives:
~ http://www.ganoksin.com/orchid/archive
Orchid Galleries:
~ http://www.ganoksin.com/orchid/gallery.htm
Invite a Friend:
~ http://www.ganoksin.com/invite.htm
____________________________________________________________________
Tips From The Jeweler's Bench - Article Archive
~ http://www.ganoksin.com/borisat/tip_sear.htm
The Jeweler's Selected Bibliography List
~ http://www.ganoksin.com/jewelry-books
Buy Orchid Jewelry:
~ http://www.ganoksin.com/shop
____________________________________________________________________
-Unsubscribe:
-Email: orchid-request AT ganoksin.com Body=unsubscribe subject=blank
____________________________________________________________________