Maybe it's me but it doesn't look like a 3/8x10..looks like a finer thread.
It’s a 3/8-10 tap. It’s hard to get a picture to focus and flash down in the hole
Center drill, 5/16 drill bit in tailstock drill to depth, tap in tailstock, run the tap in by spinning shaft
"tap by spinning shaft" Do you mean under power? I would recommend turning by hand and applying light pressure on the tailstock. Tap the same way you would with metal - 2 or 3 turns in and then back out to clear the chips. Rinse and repeat.
5/16 is a bit big for that tap
Really? Everything I have ever researched is saying for 3/8-10 tap, use 5/16 drill bit….
I don't know where you are doing your research but I do know basic machining math and constant formulas. The formula for determining a tap drill, imperial or metric, is to take the major diameter, in this case .375", and subtract the pitch of the tread from it, in this case .100 for 10 threads per inch. So the nominal would be .275". Internal threads would have a little bigger tolerance size so a 9/32" (.281) would be ideal for tap drill, where as external threads would generally be sized nominal to maybe .005" under so .370/.375, to allow clearance. Tolerances are determined based on the class of fit required.
That’s a great article. Thanks for sharing
Looks better. Next step before you finish drill and tap, Add a concave to the hole. 7/16" center drill works great for spinning between centers and also for facing off the shaft and butt without running in to the threads
Oh I gotcha…. You’re saying so there is small clearance between the joint pin and the face. That way when you face off the joint you don’t hit the pin
Old picture but Yes.
60* for shafts
Are you talking about the shaft threads or the butt that your going to epoxy the joint screw?
