BIGmiralli Frequent Poster
Joined: 17 Apr 2007 Posts: 38 Location: Boston, Massachusetts
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Posted: Tue Apr 17, 2007 2:23 pm Post subject: 1-5 acme tapping brass |
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The brass is C3600 half hard.
The tap is a 1-5 acme tandum rougher/finisher.
The part is two inches wide and the thread goes through.
The problem is that after tapping the not go gage consistantly enters the lead in threads by 2 to 2.5 turns rendering the part unacceptable.
We are boring the hole to the nominal minor diameter and threading at 100 to 150 RPM. Subsequent testing in aluminum parts yields no out of spec parts.
Any suggestions??
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Last edited by BIGmiralli on Wed Feb 16, 2011 10:38 am; edited 1 time in total |
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choseung-hui New Member
Joined: 17 Apr 2007 Posts: 4 Location: Tokyo, Japan
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Posted: Tue Apr 17, 2007 2:25 pm Post subject: |
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You have a lead problem, root cause depends on how you are tapping.
If you are allowing the tap to feed itself, the lead varies from front to back, causing material to be trimmed on one flank. If using power feed, the previous problem may exist, or the feed rate and tap lead may be slightly different yielding the same condition. |
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