# Looking for some help



## Mike8623 (Jul 19, 2022)

Im looking for someone that has a lathe that can cut 30 tpi. Mine wont.

I am making a weird tap. I can turn to diameter and send to you for threading or if you wish i will pay for you to turn a piece of oil hardening round steel to diameter and then thread to 30 tpi.

Ive tried the the section where folks make things for you, but only got recommendations on regearing my lathe.

I am looking to make a tap.

I will pay


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## mksj (Jul 19, 2022)

What is the diameter and length you need. I have O1 rod, I can cut a 30 TPI thread on my lathe you would need to heat treat/temper.


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## Mike8623 (Jul 19, 2022)

I need .645 diameter. I can cut flutes and heat treat when i get it. I need it to be  roughly 4.5 overall inches long  with about 2 inches of threads. I'll turn shank down when i get it or anything you wish to do is fine with me. I'll post a pic of a tap like i would like to end up with


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## Mike8623 (Jul 19, 2022)

Puc


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## mksj (Jul 19, 2022)

PM me with a drawing the specific details and I can see what I can do for you. I would probably cut two of them, one +0.005" deeper unless you have a female thread that I can use for sizing the tap thread.


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## Mike8623 (Jul 19, 2022)

I can mail the male and female threads i need

I


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## mksj (Jul 19, 2022)

I would just need the female. I have O1 steel rod, but if you want to turn some tap blanks down to the dimensions you want, I can thread them for you and size to the female thread. No charge for the threading, just pay for the shipping. Not sure if you want to cut the flutes before or after threading, but I can also cut the threads either way.

Maybe send both and specifics in a drawing so I can make sure the sizing is what you want.
Mark


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## sdelivery (Jul 19, 2022)

Drills and cutters .com


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## Mike8623 (Jul 19, 2022)

Mark, i made a couple of blanks today. I'll send them to you along with the female part. You can just cut threads on them or if you think they are too primitive you can make a couple. You will not hurt my feelings.

I would like .645x30 tpi.


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## Mike8623 (Jul 20, 2022)

Mark, are you there?


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## extropic (Jul 28, 2022)

Mike8623 said:


> Mark, i made a couple of blanks today. I'll send them to you along with the female part. You can just cut threads on them or if you think they are too primitive you can make a couple. You will not hurt my feelings.
> 
> I would like .645x30 tpi.


Wouldn't it be better to thread the blank(s) before fluting, so you don't have to thread with an interrupted cut?


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## pontiac428 (Jul 28, 2022)

What did you use to cut the flute profile?  It's hard to tell from the pics what you've done.  Cut em now, or cut em later, you'll need to deburr and after HT you'll need to grind to sharpen anyway, so I don't think it makes a difference.  My inclination is to thread first, but it really doesn't matter.


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## Mike8623 (Jul 28, 2022)

Ball mill


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## pontiac428 (Jul 28, 2022)

Did you offset the CL of the ball mill from the CL of the tap, or did you just cut a semicircular channel right down the middle?  Taps are usually ground with form-dressed wheels to create an acute cutting angle on the cutting side of the flute, and a flatter relief on the other.  With the right size ball and an offset tool path, you could do it with a ball mill.  I just wanted to see how you approached it.


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## Mike8623 (Jul 28, 2022)

I just turned it on my lathe then centered it on my mill and cut them from the top with a ball mill. I'm barely an ameteur.


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## Dabbler (Jul 28, 2022)

Remember, to have a tap you need at least some taper,  somewhere around 2-5 degrees of taper.  Mark can easily set up and make a taper for you, and will have to if the threading is at that exact taper, which it should be.

You can hand stone your cutting edges after heat treat to make a very usable tap...  (The will have a slight negative rake, but that sould be all right for a shop made tap)


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## Mike8623 (Jul 28, 2022)

Thanks guys


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## Mike8623 (Jul 28, 2022)

So let me ask 

On a tap at .645 +-  dia. and at 30 tpi...what degree of taper would you put in it?


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## pontiac428 (Jul 28, 2022)

Here is a bit of useful information for taps.


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## extropic (Jul 28, 2022)

@Mike8623

The graphic that John put up tells the tale.

One other problem with homemade taps is that factory made taps are not cylindrical. You can see, in figure 3, that the outside of the tap, behind the cutting edges, has reducing radius (clearance) from the cutting edge. That clearance is to reduce friction so the tap doesn't drag/gall the workpiece.

Simple homemade taps can be used for many things, but to cut quality threads in your adapters, I recommend buying a quality tap or working out the change gears required to single point them on your lathe.

Alternatively, you might sketch up the part(s) you want and ask for someone to make them for you.


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## Mike8623 (Jul 28, 2022)

Thanks, learning a lot here


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## Mike8623 (Jul 28, 2022)

I have a hard enough time asking for help as it is


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## pontiac428 (Jul 28, 2022)

Same here.   But here, people are friendly, helpful, and answer questions no matter where a person is in their shop experience.


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## extropic (Jul 29, 2022)

Mike8623 said:


> I have a hard enough time asking for help as it is


You shouldn't be shy. You've gotten a lot of good replies already. I expect that if you continue ask reasonable questions, you will continue to get useful replies.

You have at least four options in front of you. One is to carry on pursuing your homemade tap. Two is to get quotes for a "real" tap from a special tap supplier (Google "special taps"). Three is to start a new thread (in this Sub-Forum) asking if someone wants to make your parts.
Four is to get the change gears needed to cut 30 TPI on your lathe.

Actually, exercises like yours help other readers learn too. For instance, I saved the .pdf that John (@pontiac428 ) posted because it is such a clear and concise explanation of common tap geometry. If you hadn't started this thread, I might never have seen that .pdf.

One more issue about the thread you need to cut. In reply #3 you wrote that you need .645 diameter material to make your tap. How did you determine the .645 dimension? Did you measure the OD of the thread on an existing reloading die and find it to be .645 diameter? If not, what is the OD of the existing male thread you need to mate with?


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## Mike8623 (Jul 29, 2022)

Got my taps back today. I cant thank Mark enough. He really helped me out.

Thanks again to Mark and this forum for jumping in and helping when asked


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## Mike8623 (Jul 29, 2022)

Just for info

I did try to get a custom tap place to make me a couple.......they never came through

I also asked on this forum in another subforum for someome to make the tap for me, that didnt work out either......so I really do thank Mark and all of you that contributed.


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## Mike8623 (Sep 22, 2022)

Update, I can't thank this website or Mark enough for helping me.

Mark made me a couple of threaded tap blanks. I cut 4 flutes at a 7 degree angle and hardened it. Worked like a charm. I've done one adapter from scratch and rebored and threaded 3 others. I intend to make another 3-4 from scratch. I don't see any problems going forward.

You cannot find these lyman/Ideal adapters anywhere in these dimensions. They will allow me to use my larger lyman 310 dies in a regular reloading press versus spending hundreds on new dies. I was at a very frustrating standstill until this site and Mark came thru for me. Cant thank Mark and this site enough.


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## dbb-the-bruce (Sep 22, 2022)

What a great thread! (if you groaned it was a good pun).

This is pretty cool. I'm realizing now that I could grind the relief on the back side of the cutting edges on my D-Bit grinder. So I could actually create a pretty good / properly shaped blank and then thread it on my lathe. I can make just about any odd ball tap I might need. 

Thanks!


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## Mike8623 (Sep 22, 2022)

Yah, any thread your lathe will cut

Who cares bout the pun if you get to accomplish what you wish. My theory is that nothing is impossible. I left another forum because other responders were always discouraging folks from following their dreams you know the old " what ya wanna do that for kid, youll shoot your eye out" comments. Where would we be as a people if we listened to all the folks that say......that cant be done or what you wanna do that for.

Thanks all!!


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