In this case it is a die question. what is the size of the die that will thread a 1/8 inch rod properly. I have a 6-32 and a 8-32. the 8-32 is too big and the 6-32 is to small.
Shane
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
Goldilocks says 5-40 is perfect.
Ed
That's a pretty broad question. Is it to fit something specifically ?
The threads can be either metric or standard / fine or coarse thread / number of threads per inch.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
I assumed Shane was working with "standard" screws as those are the ones he mentioned. It turns out that a #5 machine screw is exactly 1/8" diameter. I chose 5-40 because that is a bit more common than the finer 5-44. Which would also work.
I think the question was quite specific. And so was my answer.
1/8 dia = .1250
The outside diameter of a #0 thread is .060
For every thread size above #0 add .013 to the dia.
Ex:
For a #4 thread the outside dia = .060 + (.013 * 4)
For a #5 thread the Outside dia = .060 + (.013 * 5)
For a #6 thread the Outside dia = .060 + (.013 * 6)
You see where this is going, right?
So as mentioned above, a #5 screw is exactly 1/8" (.125) diameter. (.013 * 5 = .065) + .060 = .125
5-40 is definately the more common thread for a #5 screw.
I learned that formula from my high school machine shop teacher 40 years ago. It is pretty basic stuff, but very few people and very few machinists actually know it.
Scott
Upon re-reading the original question, you stated that 6-32 is too small. Actually, 6-32 is still too big. It just seems too small because 6-32 is a rather funky thread size. A 32 pitch thread is a very large thread profile for a #6 screw diameter even though it is a very common screw size. If you had a dollar for every 6-32 tap that has been snapped off in parts by machinists through the ages, you would be more wealthy than Mr Trump.
I was thinking more of physical size than thread pitch. I would have to remove about 20000 of an.inch off the bar to get a 6-32 die to thread. The 5-40 is a thread that is easier to get a nut for. Should fit a 1/8 rod better too. Thank.you. shane
So I was working on threadingthe rods wwith the 5-40 die. Got to the fourth bar. All. Brass bars by the way. And the bar snapped off in the die. Neither side hasa piece sticking out. How do.iI extract the broken piece from.inside the bar.
You are about to have such fun. You need a punch and a hammer then you have to tap it out of the die. Tap it backwards. You may be able to drill it out. Neither way is fun and takes a LOT of work. I have done this more than I want to remember
I recommend tossing the die and getting another. I just don't think it's worth the aggravation to try to remove the brass. You probably can't back the brass out because it's jammed. You might be able to drill it out, but that is a very tricky operation. If the bit hits the die threads, you are likely to have an even bigger problem. But if the hole isn't big enough, you won't have taken enough brass out to collapse the remainder.
I was thinking of 1/16 drill in the press. Then take a hex wrench wedge it in and. Reverse it out of the die.
You could try working it over with a small cut off disk in a Dremel. Then punch it out.
Jim
What You need is a punch like the 3/32 one in the link. A flat piece of steel bar stock with a hole drilled in it so the die fits over the hole and with a good ''whammer'' tap it out backwards as CGW121 suggested. Next time make sure You use a good quality lube when cutting threads. The link:
https://www.mscdirect.com/product/details/86420643
You could also try a nail setter for the punch, they come in different sizes, down to 1/16''....not as expensive as the Starrett's:
http://www.truevalue.com//catalog/product.jsp?productId=63729&parentCategoryId=5&categoryId=2545&subCategoryId=571&type=product&cid=gooshop&source=google_pla&9gtype=%7Bifsearch:search%7D%7Bifcontent:content%7D&9gkw=%7Bkeyword%7D&9gad=%7Bcreative%7D.1&9gpla=%7Bplacement%7D&ctcampaign=4680&ctkwd=%7Bproduct_id%7D&ctmatch=&ctcreative=%7BCreative%7D&ctplacement=192128-43411605579
Good Luck!
Frank
And if trying to thread the whole length of a rod, back it off frequently to clear the chips. Two steps forward, one step back. If you got through any of them in one continuous shot without backing it out, you got lucky.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
7j43k I recommend tossing the die and getting another. I just don't think it's worth the aggravation to try to remove the brass. You probably can't back the brass out because it's jammed. You might be able to drill it out, but that is a very tricky operation. If the bit hits the die threads, you are likely to have an even bigger problem. But if the hole isn't big enough, you won't have taken enough brass out to collapse the remainder. Ed
A big problem with drilling( or trying to drill) is the bit will be so small it will walk all over the place and break. Best to cut your losses and get a new die.
If you try to punch the piece out, you will likely break off one or more teeth in the die. The teeth are very hard. And they are (comparatively) very brittle.
And brass is a metal that typically doesn't need lube when cutting. Though it can't hurt.
The earlier suggestion of how to use a die in the first place is good advice. Like a tap, you turn it forward "a little", then back it out to clear the chips. And go a little farther. With a die, the good news is that the chips don't try to fill up the hole--they (theoretically) just fall out as cutting progresses.
IF the rods are oversize at all, that increases the possibility of jamming/breaking. Also, if the die isn't started straight, that can cause some problems a few turns later. As in, breakage.
A bit after the fact, but they do make 5-40 brass threaded rod:
https://www.amazon.com/Brass-Threaded-Thread-Length-Threads/dp/B00G3Q52FS/ref=sr_1_2?s=industrial&ie=UTF8&qid=1491839656&sr=1-2&keywords=5-40+threaded+rod
It was when I was backing off to clear. Is when.it broke. The.lube is a special thread cutting oil specifically for softer metals. Not going.to punch it.out. the die is brand new. That was the fourth cut with it. Hate to waste 30 without giving it a shot at removing it. . The lube will make.it.tough to remove because it.is slick. Tough to get a good bite.
I would use a dremel to grind the brass to a flat surface and then use a pin vise to make a small pilot hole maybe a 1/16 inch deep; depth is not important. This will keep a larger bit from walking when you drill it. It helps center the bit. This hole need to be fairly precise.
A 5-40 die thread is .119" on the minor diameter. A 7/64th bit is 0.109. Once you have made your pilot hole with the pin vise you can now use a drill press with a 7/64ths bit to drill out the brass. There will be some left over but you should be able to remove this with a hobby knife.
The chip channels in the die should aid tou with using the hobby knife to remove the very thin brass left after drilling.
I advise against using a nail set or other object to "hammer" it out. This will only make it more stuck and most likely damage the die.
Colorado Front Range Railroad: http://www.coloradofrontrangerr.com/
If it is not a cheap die.....the brass will give way before any damage is done to the cutting teeth.....the slick lube should actually help getting it out. I've done these things many times before.....especially in building racing carburetor's. Your call....
Many threading dies are split with a screw to adjust the pitch diameter. If your die is like this, tighten the screw. This will open up the thread dia and relieve the hold on your threaded rod.
Also - for future reference, you can just buy 5-40 threaded rod. Google it.
I've been advocating tossing the die and getting a new one. After you get your new one, maybe the old die can be revisited.
What do you have to lose? It's now a reject. So, putting your safety glasses on, you might try what-the-hell punch it out. It's my belief the odds of that working a a good bit less than 50-50.
Myself, I'd go the drilling route. I've done it maybe a dozen times with a broken off 6-32 screw in a switch box. It's always worked. The big difference is that if my bit wanders a bit too close to the threads in the box, it'll just take a wee bit out. No big deal; it'll still work.
However, the die is very hard. Maybe harder than the bit. If you hit the metal of the die with the bit, it may not be pretty (remember: SAFETY GLASSES).
But.
The die has been scrapped. Ya got nothin' but a drill bit to lose. And, if it works, you can have that manly-man feeling of accomplishment. A very pleasant feeling.