Shop Talk 23: Thread Dies

There were many requests for me to talk about threading dies and I had a good opportunity to bring up the subject.
Two most basic types of threading dies are round and hex. The hex die should be used to chase and repair threads.
Round dies are good fort cutting new threads, such as on a long bolt where more threads are desired.

[dfl]

As a non-machinist I learned why there are 2 different dies for chasing threads properly. Years ago I bought a set of round and hexagonal couldn’t tell why they were different until now. Even at 70 years old it is fun learning new things. Thanks Adam.

[ajbuschm]

One thing I've learned about master machinists. They always know what the right tool for the job is and they always use it. I see so many new tools on your channel that I didn't even know were the right tool for the job.

[ss]

Appreciate you mentioning and using safety glasses when demonstrating this. Way to many YouTubers fail to emphasize and teach the importance of good safety habits on their channels. Having a Dr. operate on the sclera part of you eye (white part), while awake, with only local anesthesia injected into the eyeball, to remove embeded foreign debris, is no joke! Doctor said that he performs this procedure a couple times a month! Now ask me how I know this. Keep up the good work Adam! Thanks.

[merlin]

Something you could also mention Adam is to pay attention with any rethreading die which side of the die has a chamfer, that must always face towards the threads so the die will begin to cut gradually. Great videos!

[terry]

There are some really good people in this world and this guy is definitely one of those. So grateful he takes this time out of his busy day to explain the difference between thread cutting dies and thread chasing dies. He saved me a big headache.

[patricksullivan]

Hi Adam, it's always nice to learn something new! I did not know the diff between round & hex, now I do!! Thanks, I do enjoy Shop Talk! Keep 'em coming!

[nakamakai]

Adam, you offer the best of what YT has to offer - I learn something in every one of your videos. That's the pinnacle of content production. Thanks. Please keep them coming!

[jdgower]

Old school industrial maintenance man here, and I'm pretty up on all the "things" related to stuff like this, but I had never thought about the preferential uses of hex vs round dies.
Makes a hella lot of sense, though, and explains many of my cuss fests in trying to thread even the most basic steel rod with hex dies.
Even after 30 years of doing this stuff <and teaching others for many of those years>, I'm always thrilled to learn new things like this.
Thank you very much for stuff like this!

[andybelcher]

Hi Adam,

The split dies have to be adjustable to allow for wear. Also, it is not that they are set up to size by the manufacturer; it is the handle that allows different degrees of expansion because of the fit tolerance of the hole that the die sits in.

If you are threading a very hard material then tighten the screw opposite the split to open up the die a bit, cut an oversize thread, then loosen that screw and tighten the closer screws to cut a deeper thread, thereby saving your die doing all the work in one go and wearing out faster.

If you have to match a worn threaded hole you can open the die to make the thread a bit bigger, or, to match a worn tap or bolt/stud, close the die up to make it a bit smaller.

It is the handle that limits the expansion of the die stopping it from breaking which is what your friend did with the die nut (sorry, I am English; we use split die and die nut to describe them). Never use a split die without a handle, it will guarantee to break.

Keep up the good work

Andy

[lodgecav]

Great video Adam, I reckon probably 75% of people did not know the difference between the two types, I am in the 75%....Every day a school day! Thank you!

[isoguy.]

As a newbi these basic lessons ar so good. Thank you for passing on your knowledge onto us;
Thought for the day: Smile and the world smiles with

[josephwilson]

knew about round dies made for cutting, but glad you straightened out me on the hex dies, I've got dads old tools and they included those hex so now i know only to use those to chase.Thanks Adam

[tszabon]

My grandpa was a machinist, he died in '79 when I was just few months old. Even though I don't remember him I was always impressed by his work, machines, tools and workshop he left. He even made a small tractor for a farm he owned. I wish I could learn craft from him...

[michaeldougfir]

Most of my shop experience waslearned in school in the 1960s & 1970s. I have been wanting to review some things. Now that I found you I subscribed.

Those thread chasers were a new thing to me.

Thanks. I look forward to our time together.

[jamesstanlake]

I look forward to the SNS and Abom Adventures and now the Shop Talk videos. Great content and done the Abom way!

[mannys]

That's absolutely the right thing to do. Break a borrowed tool? Buy a new one. 👍 That's what I consider basic respect for a friend or coworker. People who return a broken tool and just shrug it off are out of this world. No clue what goes on in their heads. 🤷🏻‍♂️

[RambozoClown]

There are also split dies for chasing threads. You can put them on the good section then run them off the studs to clean up the threads. They have a tapered hex so pushing a socket over them forces the two halves together. And don't forget thread files. Great video. Shaper is getting real close there.

[scrapperstacker]

Great video!! I never knew the difference between round and hex dies. And those thread chasers are cool!!

[Huskiedrive]

I learned something new today! For 40+ years I've been using hex dies to try to cut new threads in a rod with poor results usually. Being a diesel mechanic, most tools were purchased off of the tool trucks like Snap-On or Mac. They all sell tap and dies sets, and they have hex dies in them. No where do the tell you it's for thread repair not cutting virgin threads! The tool jockeys just want to sell you something. Adam you rock!

[bostedtap]

Hi Adam, correct in all cases, the round/adjustable die is to allow for thread size based on material difference, pinch it in for tougher materials, and also for a smaller size if the thread is to be plated. You can get oversize taps when the female thread is to be plated, chassis for example. Great informative video as always.