Burrs/threads

[pp-TG]

Hi All,

Any of you have a good rule of thumb when it comes to chamfers and threads? I am looking for a good rule that works good on chamfering threads to have no burr on the starting thread any help or ideas would be great.

Thanks, Travis

[neilw20]

Put a 45 degree chamfer on the end of the thread.
Causes a nice vanishing thread, internal or scroll (flat).

[ghyman]

45° works well, as does 30°.
I typically will start the chamfer at (MinorØ - .005").
Not knowing your machine type, this may not apply: When single-point turning, I will always go back with the turning tool (after the threads have been cut) and re-cut the chamfer, followed by a final pass with the threading tool. This tends to remove the burr pretty effectively.

[Geof]

ghyman's way is the most thorough, if you want to go beyond this search for 'higbee'. This gives you a blunt start no burr thread, there have been several posts on it.

[pp-TG]

Thanks Guys,

I always end up with a crapy first thread very sharp and burry no matter what chamfer i put on I will try your suggestions.

Thanks again.