What's new
What's new

Tapping threads in hard steel

I believe carbide taps CAN be used for blind holes, but not generally by hand. See this excerpt from McMaster:
View attachment 441429


Also note, a single carbide M5 tap from McMaster is $90.

While I don't believe that price ALWAYS determines quality, or value, when it comes to carbide cutting tools, it does more often than not, in my experience. I think you just had the perfect storm of lower quality tooling, hand tapping, and presumably holding the workpiece in your hand and not in a vise?
Yes, I was holding the workpiece in my hand. It is only M5 and does not require a lot of torque and due to the holes position it was better to hold the face mill by hand. The tap was perfectly aligned with the hole when it started cutting.
So you think everything I did was wrong? The tap was only $13 a piece, but a $100 one could end up the same way. Hand tapping was the only way I could do this job. I could possibly run the tap in a chuck or a collet at low RPM and hold the face mill by hand, but I was not brave enough for that. Have you ever used a carbide tap?
 
Also to note, did you buy a tight tolerance thread tap?
But also doing it by hand can oval the holes leaving the screws to be more loosely than original, this could pose a problem with keeping the inserts tight in their seats,
fingers crossed.
The tap I have used fit the existing threads perfectly. The second tap (not used) was slightly larger.
 
Yes, I was holding the workpiece in my hand. It is only M5 and does not require a lot of torque and due to the holes position it was better to hold the face mill by hand. The tap was perfectly aligned with the hole when it started cutting.
So you think everything I did was wrong? The tap was only $13 a piece, but a $100 one could end up the same way. Hand tapping was the only way I could do this job. I could possibly run the tap in a chuck or a collet at low RPM and hold the face mill by hand, but I was not brave enough for that. Have you ever used a carbide tap?

While I was being a jerk earlier (it's fun), wrong might be a strong word. I think you did most of the things that you're not supposed to do with a carbide tap. I have a couple here that I bought for a project in hardened steel, but I ended up not needing them. I think I paid like $130 for each of em, so I'm pretty sure they'll work on whatever I eventually use them for.
 
I paid $31 for the face mill and a box of inserts including shipping. Rest assured, after I fixed the threaded holes this mill is every bit as good as your overpriced one. That is if you have one at all. The insert screws are just fine, there is no need for better ones.

I stated this thread hoping to get some experience with carbide tap operation and I still hope some of you guys know how to deal with them. Share your experience please. I would like to learn from you.
If you have nothing to contribute, don't respond to this thread.
After he gets this silly screw issue fixed to his satisfaction he will surely be back wondering why his garbage $2 inserts break and chip.
 
After he gets this silly screw issue fixed to his satisfaction he will surely be back wondering why his garbage $2 inserts break and chip.
There's probably nothing wrong with them. Won't compete with good inserts on surface speed, but otherwise fine.

I am a premium tooling guy through and through, but ever since I bought a load of Chinese insert drills to stop my Sandvik ones getting beaten up on low value jobs I have to say that a lot of the cheap shit on aliexpress is much less shit than I ever expected.
 
Use an allen wrench to hold the screw and hand grind a couple of threads off of it at a 45 degree angle while spinning the screw.

I finally looked at the link provided and there was only a two star review on the cutter, gosh, what did you expect?
 
When you've hand tapped an M16 in a 56 Rc backing plate, come back and we will talk.

:cryin::bawling::fight::vomit::wrong::ack2:

Whatever sins I committed I pray I will never do that again.
 
I was going to offer some constructive advice but certainly not after this comment.
When you quote somebody, make sure you quote the whole sentence.
I was told this board is very unfriendly to people with less than the best equipment and tools and now I experienced it on my own. Nobody except TeachMePlease have even tried to answer my questions. I did not ask how to shorten the insert screws, I asked how to use a carbide tap properly. I am sorry I asked a question. Will not happen again. Have a good day.
 
When you quote somebody, make sure you quote the whole sentence.
I was told this board is very unfriendly to people with less than the best equipment and tools and now I experienced it on my own. Nobody except TeachMePlease have even tried to answer my questions. I did not ask how to shorten the insert screws, I asked how to use a carbide tap properly. I am sorry I asked a question. Will not happen again. Have a good day.
When you ask a guy how to fish, and the first response is, that pole is crap, I would get a different pole, because he's been there done that.
Your response shouldn't be WELL MY POLE IS AS GOOD AS YOUR POLE!"

There in lies the error.
 
When you quote somebody, make sure you quote the whole sentence.
I was told this board is very unfriendly to people with less than the best equipment and tools and now I experienced it on my own. Nobody except TeachMePlease have even tried to answer my questions. I did not ask how to shorten the insert screws, I asked how to use a carbide tap properly. I am sorry I asked a question. Will not happen again. Have a good day.

Oh boo hoo, now you're playing the victim card.

Here...
Here is the whole sentence AND the one after for good measure.

"I paid $31 for the face mill and a box of inserts including shipping. Rest assured, after I fixed the threaded holes this mill is every bit as good as your overpriced one. That is if you have one at all."

Who is being "unfriendly" in the 2 sentences I quoted?
🖕
 
Here is the whole sentence AND the one after for good measure.
"I paid $31 for the face mill and a box of inserts including shipping. Rest assured, after I fixed the threaded holes this mill is every bit as good as your overpriced one. That is if you have one at all."

Who is being "unfriendly" in the 2 sentences I quoted?
🖕
Exactly right. What the OP is saying in that post is that the professional machinists who this site is set up for are idiots who waste money on overpriced equipment when cheap crap is just as good. He clearly thinks he is smarter than the professionals here so I don't understand why this genius is even asking basic questions about tapping hard metal since he knows it all.
 
Exactly right. What the OP is saying in that post is that the professional machinists who this site is set up for are idiots who waste money on overpriced equipment when cheap crap is just as good. He clearly thinks he is smarter than the professionals here so I don't understand why this genius is even asking basic questions about tapping hard metal since he knows it all.
You said that, not me. I have never called anyone here an idiot. I am happy with my cheap tool and will let you enjoy the expensive one.
 
Then do you think smart experts buy overpriced tools?
You still want to continue this useless discussion? I don't know who the smart experts are, but if an old, experienced machinist always used Greenfield taps (let's say $100 a piece) and could get away with it, he is not going to buy and try a cheap ($10) tap. So he will never know that cheap tap could be not so bad.
 
You still want to continue this useless discussion? I don't know who the smart experts are, but if an old, experienced machinist always used Greenfield taps (let's say $100 a piece) and could get away with it, he is not going to buy and try a cheap ($10) tap. So he will never know that cheap tap could be not so bad.
Clearly you want to continue and now to try to mislead everyone. You were not talking about taps, you said your cheap ass face mill would be better than the overpriced ones the professionals here buy once you worked your magic on it.
 
All right fellas, take it easy. I feel like there is a bit of a disconnect here between guys who use these tools every day all day for work, and those who only use them occasionally. For the former, they can't take the risk on cheap tools that may or may not work. The tools need to get the job done, first time, every time. For the latter, if the tool doesn't do the job, who cares, they can wait and try another cheap one. Both sides need to realize that what is best for them may not be best for everyone.

The professionals here are going to be a little disdainful of such a "who cares, try again later" approach because it makes zero sense for them and their customers. No need to argue about it. Just understand it.

In my personal experience, some of the cheap inserts are okay. Some are absolute garbage. The problem is it's difficult to tell which is which before you buy them, and you may well find that one batch of a specific insert is great and the next sucks, even if it's the same brand name/grade/etc. The expensive stuff is expensive because it just plain flat out works, reliably, every time.
 
It's impossible to answer with any certainty the OP's question about why that cheap carbide tap chipped. There's too many variables and unknowns. You'd have to run a side by side comparison with a brand name and known quality industrial level carbide tap in the next hole of that face mill and then see if the same happens. Since that's not ever going to happen.................

But I figured out a long time ago any of the bottom of the barrel cheap carbide was always extremely weak and I guess crumbly would be the best description. The OP is either ignoring or doesn't yet understand enough and is illogically assuming that all carbide has to be equal as long as it says it's carbide. My best assumption for that soft, poor tool life and poor resistance to even minor shock loads is that there using sub standard quality and produced carbide, same for the binding agents, sintering process etc. And without question skipping or ignoring some of the basic manufacturing steps to meet that out the door price point. If even the threads were too short, then what else is out of spec on that $31 face mill and inserts? Thanks, but even at a hobby level I'll pay what it costs for something brand name that actally does what it says it will.

Sandvik Coromant has an older YT video they produced showing the basic and mostly automated steps behind the production of replaceable carbide tips.
Watching it even once should be more than enough to appreciate we can still buy the better industrial grades of carbide for as cheap as it is. That dirt cheap price virtually guarantees there cutting corners at the end users expense in every way possible. 99.999% here already know all this, and it's completely illogical to try and argue otherwise. Yeah I guess you could also argue a Yugo or Russian Trabant are just as good as any Ferrari if you've never once seen never mind driven one. 😀
 
That is generally the fault mode of most of the cheap carbides I've tried. They chip and fracture away too easily. No toughness, so they lose their edge rapidly. I appreciate the desire to find less expensive carbide inserts, but it just isn't worth all the failures, to me. Especially if one of them takes out the milling cutter.
 








 
Back
Top