threading 1/2" rod ??

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I need some 1/2" threaded rod 4' long so I bought a stick and a die to thread the ends. Surprise...much to thick to even get the die started so I grind the ends abit and find out that the threads are much smaller then half inch. Just how much am I going to need to grind down before I can expect a decent thread? The machinery handbook only discusses rolled and lath which doesn't help me very much. I do have a dial micrometer but not a target size.
Reply:Well what is the O.D. of the rod right now?  Is it hot rolled or cold rolled?  Hot rollled will be a ways over 1/2" in diameter.  A lathe would be ideal to do this, but just like me, you do not have access to one right now.  It takes alot of work to cut it down close to evenly, but could be done.  It would be handy to use some long strips of sand paper, and wrap it around and "saw" back and forth with it.  But, in all reality, it would be more feasible to get some true 1/2 rod, or use a piece of 1/2 all thread, or to weld threaded bolt ends onto the rod you have, all depending on your application.
Reply:As Bolt said, check the diameter. If it is close to nominal there are several die options:First, check the die on a 1/2 bolt. Make sure hte die is on size. Don't use a hot dip galv bolt-they are generally oversize.Second, is it a threading die? or is it a chaser? A chaser won't cut threads, only dress them. MOST chasers are hex shaped, but there are some that are round and fit a standard die stock.Is the die adjustable? It may be set undersize. Many are when shipped, as the adjusting screw is just run in loose.Are you using the lead side of the die? Only one face will start threads. (one way to ID a round chaser: a short lead on both sides rather than a long lead on one)Did you use the proper threading lube?Starting a die by hand can be a real pain. It must be dead straight. You must force the proper feed.If the die checks good, and the diameter of the rod is good,a trick that I have used is to set the die to cut a bit oversize, start the threads, cutting far enough to get about one full thread, then remove the die and reset it to proper size (this requires a either a standard, or a high quality bolt) and run the full thread. The initial, slightly oversize, thread allows the die to start at the correct size. A better method is to run the whole thread a standard oversize first... most sizes can be had in an oversize and an underize for rethreading a full thread where the original is partially stripped. Over is for stripped hole, under for stripped external. Obviously, in that case, the other part needswork to make the correct fit. As I recall, for 1/2" and up, 1/32 over and under is common
Reply:Why go through all of this trouble?Just go buy some 1/2 inch threaded rod.You'll be a much happier guy..............
Reply:you are right. after several attempts to grind the end down to the correct diam. I bought several bolts, cut the heads off and welded them to the ends of the rods. Seems like it should have been easier to just thread the ends.
Reply:Glad it worked out, I was actually saying to just buy a 4' length of threaded rod,but either way it worked out for you.