Thread milled blind holes: Best practice to use standard threads in thread milled designs?

Forum|Forum|2 years ago
June 29, 2023
1 reply
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Creo Parametric 7

I have multiple designs in process that will have thread milled holes in them. What is the best practice for standard thread milled features in Creo? The standard tapped holes are not out of the box configured to deal with these features.

Is anyone aware of the existence of an open-source custom hole chart for thread milled holes for UNC/UNF threads? Would custom hole charts be capable of dealing with thread milled holes?

I am open to other solutions (UDFs) etc. if there is an advantage to using them.

Best answer by StephenW

My quick fix is to edit the drill point angle to 180 and it creates as a flat bottom.

Patriot_1776

22-Sapphire II

'Sup Tom! The thread callout should be the same regardless of whether it's cut with a tap or thread milled. If it's say, a .750-10 UNC-2B, it's that regardless of the method used to machine it, and so the initial milling for the minor diameter should have the same diameter as if you drilled the hole with the standard tap drill. If you DEVIATE that, and make your own minor diameter, and pitch, etc., then that's a whole 'nuther story.

So, simple answer is just call out what the thread IS (use the standard Creo hole), and then the burden is on the Machinist to make it conform to the standard...as it should be.

tbraxton

Author

22-Sapphire II

I have standard holes in the model now. The issue is that there is a drill point created when using a standard hole that is problematic in the design, hence the use of thread milling in a blind flat bottom hole.

Another way to ask the question is in Creo 7 is it possible to eliminate the drill point when using a standard hole feature. I want a flat bottom hole.