Hello -
Anyone out there able to give me information on Blunting Buttress and Acme threads? For the first time in my 20+ years experience, I am getting a few jobs that require blunt threads. I have an idea of what needs to be done (basically get rid of the very sharp edge, milling to about a full thread "down" so the thread starts almost at full thread width), but not 100% on that ... are there specs or drawings or something that tells me specifically what needs to be done so I can program the machines correctly?
On one of the drawings for a buttress thread, the drawing just says, " 5" x 4 Buttress Thread, Blunt Starting Threads ". That's an internal thread. Nothing more about the blunt starts on that drawing. The other says, " 16.7355" x 0.5 Buttress Thread ... Remove knife edge & sharp corner of buttress thread, back to half thread thickness ". Another internal thread. That one at least has some description. The one with the ACME thread, (an OD thread), says, "15° Higbee .03 flat at crest or burr sharp thread start .03 width". I can interpret the ".030 flat at crest and ... .03" width", but not sure how the 15° plays into that, and what's a "Higbee"?
Anyway, I've looked some on the internet and surprisingly haven't come across any specifics. Are Higbee and Blunt start the same thing? Probably not. Anyone know anything about these? Thanks.
Anyone out there able to give me information on Blunting Buttress and Acme threads? For the first time in my 20+ years experience, I am getting a few jobs that require blunt threads. I have an idea of what needs to be done (basically get rid of the very sharp edge, milling to about a full thread "down" so the thread starts almost at full thread width), but not 100% on that ... are there specs or drawings or something that tells me specifically what needs to be done so I can program the machines correctly?
On one of the drawings for a buttress thread, the drawing just says, " 5" x 4 Buttress Thread, Blunt Starting Threads ". That's an internal thread. Nothing more about the blunt starts on that drawing. The other says, " 16.7355" x 0.5 Buttress Thread ... Remove knife edge & sharp corner of buttress thread, back to half thread thickness ". Another internal thread. That one at least has some description. The one with the ACME thread, (an OD thread), says, "15° Higbee .03 flat at crest or burr sharp thread start .03 width". I can interpret the ".030 flat at crest and ... .03" width", but not sure how the 15° plays into that, and what's a "Higbee"?
Anyway, I've looked some on the internet and surprisingly haven't come across any specifics. Are Higbee and Blunt start the same thing? Probably not. Anyone know anything about these? Thanks.