(07-30-2012, 05:57 AM)Mayhem Wrote: I ground a 60* bit out of a 1/2" blank and checked it against a gauge before honing the cutting edge. I ground 10* relief angles on both sides and left the top flat. I am wondering if I need more side relief, given the helix angle of a 6tpi thread? I don't really know/understand the whole geometry of the tool/helix angle but thought it may be something I should consider.
I don't understand it all either Darren, but I think you need a whole lot more relief than that for a 6 TPI thread. You may have a vertical shear bit there, instead of a threading bit.
Have you tried putting some Dykem on your side relief cuts to check for rubbing?
Willie
Willie