threading question-help-muzzel break

[emmie]

trying to cut 1/2x24 threads,for muzzel break. useing 1/2" drill rod to practice set up. bit is carbide full cut type. rod is in 1/2" a 5C collet extending 1 1/2" out from collet ,cutting 1" long thread. cutting right to left.
haveing used 1/2 cut tail stock spindel and not,am I keep getting flex in the rod.
thead is cut to deepth at right end,but not at left. have cut many threads on new rem and sav barrels,but never put on muzzel break befor.
what is mad cow makeing me miss in this project?

thank you for your time
emmie

 

[Clipper]

Drill rod is annealed to basically cold rolled hardness. Tool pressure is likely distorting the rod away from the cutting edge. Try progressive compound .005" passes with your compound set at 30*. This will cause less distortion. You also may be able to clean up your drill rod with a die. You can use your tailstock and a drill chuck or drill taper to put pressure on the die stock to keep it square. Just make sure the die stock handle can swing over the lathe bed when you reach full length of your threads, so you can just let go.

 

[jmorris]

What do you have that is 1/2 24tpi?

 

[emmie]

muzzel break

 

[james layman]

muzzle brake

emmie I believe you are making this from scratch. Another example, I bought a demilled new carbine barrel. Threaded muzzle with 1/2 x 28 die. Bought a cheap break that fits AR 15. Had to drill end to clear .30 cal. Used 2 crush rings to orient the break. I would be glad to loan you the die if needed. best to you, Jim

 

[Zeke/PA]

Do yourself a favor and use a High Speed lathe bit instead of the carbide.
Grind a precise 60 degree tool bit and set your lathe compound at 28 degrees.
Use plenty of cutting oil.

 

[Howard Roark]

You are definitely taking off too much material in a single pass to get that much flex. As others have said take much smaller cuts and make multiple clean-up cuts just as you reach TD. When no more material is removed and reach final TD that means that the piece has flexed no more and you're done.