FLAT THREADS

was on a lathe then by hand.........and yes am aware of the bigger die side to start

to start with I didnt have a hexagon die holder to use off the TS so had to put the die in the chuck, then the 1/2 6061 rod in the TS chuck and turned the chuck by hand till I got some threads. then turned the rest by hand in a vise with a die wrench
>>>>turning by hand with the wrench was hard to turn so maybe thats why the stock had to be smaller like everyone sez, but would the threads come out diffrent ??
 
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With a smaller OD than required the thread doesn't get fully formed. I usually do it with a tailstock die holder, and even with 10" of handle it's kind of tough cutting 1/2-13 on steel. 6061 shouldn't be that bad though. Single pointing that size is easier. I do have some Irwin stuff and it works but higher quality dies and taps work much better.
.500 Od for outside threads
27/64 drill for 1/2-13 tap
 
Try single threading on the lathe to remove most of the material, then use the die to clean it up and get it to final dimension. The single pointing will be more concentric and make the die work a lot easier.
 
First let's make this clear, the stock should be 1/2 in. diameter to produce a 1/2-13 male thread. You don't need a chart for this one.

You mentioned that you are using a hex die. It is possible that it is intended for thread repair and not for cutting new threads, which might explain why it was hard to turn. Regardless, 1/2-13 is a relatively large, coarse thread and is going to be hard to turn. Getting the die started (and started straight) can be made easier by several things including a large chamfer, a short section of reduced diameter and using the tailstock on the lathe to push the die as you turn it. @machPete99 's suggestion to single point the thread before finishing with the die is a good one.
 
I think most hex dies are for rethreading to cleanup an already made thread. Like everyone has said the work diameter should be the thread diameter. BUT since the points don't contribute much if anything to strength, turning the stock down a few thou makes life easier. If the die isn't started dead square it will try to cut ever deeper on one side as it advances. Same with taps. A set of high quality alloy tap & dies are worth their price. Get the adjustable round dies for making new threads.

I finally broke down and got a tailstock die holder. Works great, much easier than trying to start a die any other way.
 
Larry$ said:
I finally broke down and got a tailstock die holder. Works great, much easier than trying to start a die any other way.
Click to expand...
No need to buy one, this is an excellent beginners project. Get the tool and some experience in the bargain.
 
MrWhoopee said:
No need to buy one, this is an excellent beginners project. Get the tool and some experience in the bargain.
Click to expand...

Im all for making my own TS die holder just dont have the right size stock on hand
 
speaking of thread info>>>>>>>>>.I have a 5/16 -18 tap and the chart sez 250 2570 2610 2656 2660
for the hole size to be tapped, which size drill would I use ???
 
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