Drilling the end of a threaded rod

[francist]

Francist, great idea! I was going to warn to never chuck a thread in your jaws diectly, but to turn a round collet and split it - but your nut idea is far better!

Thanks, although I'm sure I saw someone else do it and picked it up there. Not much is really new anymore, eh. The added benefit of the split nut is that it can be easily used in a shop vise as well for those times when you want to saw a fastener off but don't have enough room on the waste side to grab it.

-frank

 

[rwm]

I love the copper wire idea. Thanks.
Robert

 

[oskar]

Great idea Frank, thanks

 

[mmcmdl]

Got any soft jaws ? I've never marred a thread in a collet nor a 3 jaw even with hard jaws . Use a little finesse when tightening and don't use a cheater bar ! 1/4 -20 doesn't take much to drill and tap .

 

[oskar]

Will give it a try, thanks

 

[homebrewed]

For smaller screws I use a section of nylon rod. I chuck it in my 3-jaw and through-drill a hole that is slightly larger than the screw. Insert the screw and crank the jaws down. The nylon deforms around the threads and holds the screw in place, good enough to cut screws down to the size I want. I made several of these for numbered screws (#4-#10) and some metric ones in the same size range. I've also made split collets out of aluminum, but it requires an extra machining step (cutting the slit).

This approach won't necessarily give you a precisely centered screw but it's been "good enough" for most of my requirements.

 

[kwilliam]

If you want to drill / tap threaded rod precisely, then use a four jaw chuck with copper sheet wrapped over the threads.
Then arrange to hold a small piece of copper sheet outside of the chuck that rests stationary on the threads while the chuck can be rotated.
Then have your dial test indicator sit on top of the copper sheet.
Adjust four jaws until desired run out is achieved.
Drill and tap aligned hole.

 

[RJSakowski]

When modifying threaded rod, I will use three nuts. As Mike stated, I use two jammed together to secure the threaded rod but I also have a third nut on the thread to engage the back of the chuck jaws. This prevents the rod from twisting due to the relatively short contact area of the nut.