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06-23-2011, 01:29 AM #1
threading barrel tool recommendation
I am new to the metal hobby. I would like to know what threading tool to buy in order to do a barrel threading job (1/2" 28tpi, 5/8" 24 tpi). Does it matter which tool to get for different toolpost size (BXA or CA)?
I was looking at MSC and couldn't figure out what I need to get. Any helpful recommendation is greatly appreciated.
06-23-2011, 06:00 AM #2
A HSS lathe bit and a grinder and a threading guage, I grind my own threading tools.
06-23-2011, 06:43 AM #3
If you really feel like abusing yourself you could even use an old lantern toolpost instead of those fancy quick change toolposts that you listed. You can get a lantern tool post and some holders really cheap because almost everyone hates them.
Seriously though, Get anything that will hold a HSS bit perpendicular to your work, grind the HSS bit to 60 degrees. Use your threading gauge (often sold as a "fish tail") to get the angle right and practice. You will pick it up in no time. Look on youtube, piles of videos.
Best of luck.
06-23-2011, 07:01 AM #4
Tool post size is largely irrelevant.
BXA tool holders will not grip quite as large a tool as a CXA, but select a tool holder that is approprate for the swing of your lathe. Get one that is too big and the tool wont drop below the center line of spindle.
If you chose to use a insert type threading tool, pay atention to the part number code. The tip radius of the tool is indicated in that code, and you will need a small tip to cut 24 to 28 tpi threads. Larger tip radii are use for larger threads.
A simple 60 degree triangular insert can be used to thread, if you dont have to get close to a shoulder, and the tip radius is fine enough. I have been known to use them to rough out a thread and chase over it with a die to be sure I had it right.
Respectable threads can be cut with a hand ground tool. Just take your time grinding the tool and get it right. The form has to be right to get a thread that works well. From the size you are talking about, I assume its barrel end work for muzzle breaks. Thats a little more forgiving than breach end work.
The most important tool you need for cutting threads is a copy of the machineries handbook. It contains tables with the tolerance bands for most threads you are likely to encounter. This allows you to get the OD right before starting to cut the thread.
If you have not cut threads before, practice on some bar stock. Picking up the thread with a thread dial takes a little practice. Pulling out at the right time takes a little more. Getting your tool to preform properly, (feed, speed, depth of cut) is also a bit of trial and error work.
06-23-2011, 10:27 AM #5
What kind of barrels are that size and have that thread pitch.
06-23-2011, 03:39 PM #6
My guess would be for flash suppressors on AR-15 and AR-10 stuff.
06-24-2011, 12:54 AM #7
It may be for supressors, whatever it is for the bore needs to be in the center before threading.
I saw a guy with a muzzle brake off center and he was wondering why the gun shot worse after the brake was installed.
06-24-2011, 06:30 AM #8
1/2-28 is the common thread for 22 / 223 barrels . for brakes flashiders and cans ..
9/16-? and 5/8-24 are common for 30 cal us barrels .
most foreign stuff uses 14mm-1mm LH thread
06-24-2011, 08:55 AM #9
Not an answer to your question but you may want to look at MSC's sister company Enco, mostly the same stuff at a cheaper price. I just received the Grizzly tool catalog in the mail; there is a lot of miscellaneous tools that I didn't know were made
Good luck and practice,
07-02-2011, 01:38 AM #10
The attached link will help you.
YouTube - ‪High Speed Steel Lathe tooling.AVI‬‏
I also have a threading video there.
07-27-2011, 08:11 AM #11
We just learned to thread barrel's, ordered pilots for .22 and .30 cals for now. We are threading for suppressors 1/2x28 and 5/8x 24. Using Kennametals 5/8" holders with carbide inserts. Had problems till I learned that the markings on my lathe was off the y axis and not the x axis. Once we set up the compound at 29 deg off the x axis, the threads came out perfect. My lathe is a 26 year old machine from taiwan, and it is very accurate. We made a spider for the back of the spindle to adjust rifle barrels to within .0002" off the bore.
07-27-2011, 09:04 AM #12
07-28-2011, 09:07 AM #13
If doing muzzle brake and suppressor threads, a hand ground HSS bit works fine..
Not much room for an end of thread relief groove. The barrel shoulder varies in diameter on different barrel types.
Cut away left portion of a standard hand ground HSS threading tool, allows you to thread to shoulder better.
Carbide inserts are hardly needed on a manual lathe... even at 70 RPM and 28 TPI, that shoulder comes up quick. You just can't get near proper carbide SFM, threading to a blind shoulder on a manual lathe... (there are a few auto crosslide kickout manual lathes out there..)
07-28-2011, 10:08 AM #14
Your post makes it sound like a production operation, not a hobby. Are you working on other peoples firearms with this level of experience? Are you knowledgeable regarding the legal aspects?
08-28-2011, 12:03 PM #15
Working on my own guns
We plan to do work on our own guns. But later with more experience we my do work for friends too. I am very mechanically inclined, acquiring the proper tools and skills needed for firearms.
08-31-2011, 03:46 AM #16
08-31-2011, 05:10 AM #17
09-01-2011, 02:31 AM #18
IMHO the muzzle threads should be single pointed most of the way at least, with the proper setup they can be single pointed 100%....but doing it 95% and then running a die to knock the fuzz off will still result in good concentricity. Some guy might want to put an expensive suppressor on that thread someday.
09-02-2011, 01:58 AM #19
I would recommend getting the largest that you can fit your tool holder and still have clearance to work.
When I thread barrels (either end) I use a 3/8" or 1/2" carbide tipped threader bit in my BXA tool post. This makes very nice threads with no flexing of the bit/holder etc.
I used to thread with a 1/4" HSS in a lantern tool post, which afforded a lot of clearance when I first started out. I also used a rather large relief groove in those days. Now I sometimes don't even use a relief groove threading 1/2 - 28's for AR-15 flash hiders etc.
09-02-2011, 02:48 AM #20
Any of the M series hss tools can be ground to suit. I, had made a hardened,
and ground fixture, a number of years ago, when chasing threads was an "almost daily" job. A fixture, used on a surface grinder, allows the regrinding of the tool, part way through the job, without any worry of resetting the angle. A "Uni-Vise", or one of it's clones, is a big help on lots of other jobs around the shop, also.