Thread: Rigid Tapping Struggles

Also, I was researching a little about tap collets for my ER tool holders. Do you recommend the square drive collets? I have a decent amount but none for the smaller taps. Thinking about buying some for those.

Thanks,

CM

Originally Posted by metalmadness

Soooooo what kind of coatings do you recommend for aluminum? Guhring has an insane amount of coating options, so I don't even know where to begin

For general machining of wrought alloys completely uncoated is fine, polished flutes the better. If you're getting into production numbers then you're going to want aluminium specialised coatings like ZrN and CrN. Taps specialised for cast aluminium are a bit outside my sphere of knowledge, but DLC or TiAlN for abrasion resistance.

I don't use Guhring taps, but I imagine if you look only at taps that are specific to aluminium, the number of available coatings will not be too many.

Originally Posted by metalmadness

Also, I was researching a little about tap collets for my ER tool holders. Do you recommend the square drive collets? I have a decent amount but none for the smaller taps. Thinking about buying some for those.

Thanks,

CM

I don't use them, never needed them. I've never had a tap slip in a plain ER collet that didn't slip for a good reason. Just use some common sense about using appropriate size collets for the size of tap...

Originally Posted by gregormarwick

For general machining of wrought alloys completely uncoated is fine, polished flutes the better. If you're getting into production numbers then you're going to want aluminium specialised coatings like ZrN and CrN. Taps specialised for cast aluminium are a bit outside my sphere of knowledge, but DLC or TiAlN for abrasion resistance.

I don't use Guhring taps, but I imagine if you look only at taps that are specific to aluminium, the number of available coatings will not be too many.



I don't use them, never needed them. I've never had a tap slip in a plain ER collet that didn't slip for a good reason. Just use some common sense about using appropriate size collets for the size of tap...

For aluminum just go uncoated. Not sure how much difference like a TiB2 or Zrn would make a difference. Maybe increased surface footage?

As far as Guhring taps are concerned, Im looking at the catalog and most are uncoated/polished. The coatings offered are TiN...which I assume helps with lubricity and increased SFM. They also have TiCN but not sure what differentiates it.

I may skip the tap collets, but I definitely do need to order some regular collets that are the correct size. Collets being over compressed might be contributing to the issue.

Thanks,
CM

Originally Posted by metalmadness

Also, I was researching a little about tap collets for my ER tool holders. Do you recommend the square drive collets? I have a decent amount but none for the smaller taps. Thinking about buying some for those.

Can't imagine anything 1/4" or smaller slipping in a decent ER collet, the tap would just break off.

Regards.

Mike

Originally Posted by metalmadness

As far as Guhring taps are concerned, Im looking at the catalog and most are uncoated/polished. The coatings offered are TiN...which I assume helps with lubricity and increased SFM. They also have TiCN but not sure what differentiates it.

I've seen Al build-up on TiN and TiCN taps so I stopped using them and am now just plain bright uncoated.

Regards.

Mike

TiCN is by far the worst offender for build up in aluminium. Usually when this is discussed on here a few people will pipe up stating that they use it all the time in aluminium and it works fine, but my advice is to avoid it at all costs for aluminium. TiN less bad, but still bad. Both can be mitigated greatly by the choice of tapping fluid. TiN will gall in aluminium using the Hysol that we use, but never with cutting oil. Just another variable.

I have a few CrN and DLC coated taps that I've acquired over time, but our numbers never get high enough to say objectively if there's much difference. Uncoated and polished makes up 99% of our alu taps.

We have a semi production job where we tap M20 holes in 30CrNiMo8 +QT (basically 4340QT). Tap is in a plain ER40, never gives any trouble. Last time we ran, night shift operator interrupted the cycle before the drill, and restarted after the drill. I have no idea what he was doing but w/e. Tap pushed up inside the collet with no drama other than a scored collet bore. Operator put next part in without realising and continued, I eventually got called after he realised that the last half a dozen parts had holes with no threads in... The damage was limited to some rework and a new collet. Had that been a tapping collet it would have been a lot worse... (big machine, doesn't care about such events)

Metalmadness: I was put on a big horizontal that part of the program was tapping 1"-8 holes in aluminum 3" deep. They kept breakig taps. This old machine ran for on mylar tapes. I started experimenting with feed rates on the taps. Found out that by reducing the feed rate 10 percent, every thing went well. Could your machines feed rate be off a little? Good luck.
JH

Originally Posted by gregormarwick

TiCN is by far the worst offender for build up in aluminium. Usually when this is discussed on here a few people will pipe up stating that they use it all the time in aluminium and it works fine, but my advice is to avoid it at all costs for aluminium.

I think you mean AlTin.....

TiCN is fine

Originally Posted by Rstewart

I think you mean AlTin.....

TiCN is fine

Not in my experience. I've had TiCN Kennametals load up whilst running in 6061.

Regards.

Mike

Originally Posted by Rstewart

I think you mean AlTin.....

TiCN is fine

Yes and no.

TiAlN / AlTiN is supposedly technically more likely to adhere than TiCN, but my experience has been that TiCN is the worst culprit. I have theorised that it's because TiCN coatings are thicker than TiAlN in practice and the duller edge aggravates the problem.

Overall, my experience has been that any coating not explicitly designed for aluminium tends to build up, and the single most critical secondary factor is coolant - coolant that works well in aluminium can prevent build up on coatings that are otherwise prone to it, which is why there are so many conflicting opinions on the matter.

I know that the coolant I use does not work very well on aluminium, and I take precautions accordingly.

SO I am settled on uncoated taps for AL, but looking at form taps, they all look like they are TiN coated. Unless anyone has a source for uncoated form taps?

Originally Posted by metalmadness

SO I am settled on uncoated taps for AL, but looking at form taps, they all look like they are TiN coated. Unless anyone has a source for uncoated form taps?

Search Thredfloers| Balax Inc.

Not sure if you can buy direct though. MSC carries quite a bit of the Balax line. Only thing we can't find are the extended taps, for those we go directly to Balax, or our MSC rep does maybe?

Weird they don't offer uncoated?

Originally Posted by gregormarwick

........I also have Hurcos and there is a rigid tapping monitor somewhere in the integrator support section that displays realtime servo-spindle sync latency during rigid tapping. I have never had to use it so I can't help with that, but it's there.

When I have run into questions whether the machine was having sync issues, I'd recommend switching from a collet to a floating holder yet still keep the rigid tap cycle. Then, if the problems were eliminated or greatly reduced, I'd be pretty sure it was a machine issue and investigate that. If the problem remained then I'd call it an application or tooling issue.

Originally Posted by metalmadness

SO I am settled on uncoated taps for AL, but looking at form taps, they all look like they are TiN coated. Unless anyone has a source for uncoated form taps?

I know some folks hate MSC, but I don't have any complaints. They stock zillions of form taps, from various makers, coated and uncoated. The 25-50% extra I might spend at MSC is easily offset by the variety offered, ease of purchase, and speed of delivery.

Regards.

Mike

Yea I dont hold anything against MSC, but htey are pricey. Our shop was using Accupro endmills before I came on board. Once I realized I can get better tooling for half the price through Helical Solutions and Harvey, well I never looked back. Accupro endmills are wildly overpriced.

Sometimes I just need stuff and don't want to deal with a distributor or my main distributor doesn't carry a certain line. MSC saves the day.

I will check out what they offer for form taps!

Originally Posted by metalmadness

Yea I dont hold anything against MSC, but htey are pricey. Our shop was using Accupro endmills before I came on board. Once I realized I can get better tooling for half the price through Helical Solutions and Harvey, well I never looked back. Accupro endmills are wildly overpriced.

Sometimes I just need stuff and don't want to deal with a distributor or my main distributor doesn't carry a certain line. MSC saves the day.

I will check out what they offer for form taps!

Hmm...? Not seeing that with Harvey, but agree certainly better quality

Harvey Tool

https://www.mscdirect.com/product/details/62773494

Neither with Helical.

Helical Tool

And if you factor in MSC's *legendary* "discounts" You could easily expect to pay $10 for that Accupro.

edit: MSC link shows a 2 flute, but if you search 3 flutes, they have a few in the $10 price range as well.

I don't know if they're easily available in the states, but Reime Noris (up there with Emuge as the best taps I have ever used) and UFS both do aluminium specific form taps with some application specific coatings.

Originally Posted by Mike1974

Hmm...? Not seeing that with Harvey, but agree certainly better quality

Harvey Tool

https://www.mscdirect.com/product/details/62773494

Neither with Helical.

Helical Tool

And if you factor in MSC's *legendary* "discounts" You could easily expect to pay $10 for that Accupro.

edit: MSC link shows a 2 flute, but if you search 3 flutes, they have a few in the $10 price range as well.

Well it depends on the tool. For our CNC roughing, we use 3fl ZrN coated carbide endmills. So for an apples to apples, that is what I compared when price shopping. Maybe for uncoated stuff that is more "generic" from Accupro, pricing is more affordable. But ZrN for our applications is far superior.

Helical sells them for about $50 through our distro. MSC sells them for $85.
https://www.helicaltool.com/products...are---35-helix
https://www.mscdirect.com/product/details/65250193

What are these "legendary" discounts?

IMO helical are better anyways, as far as tool life and performance. But we were paying asking price at MSC for our tooling so that may be a factor in play

Originally Posted by metalmadness

Well it depends on the tool. For our CNC roughing, we use 3fl ZrN coated carbide endmills. So for an apples to apples, that is what I compared when price shopping. Maybe for uncoated stuff that is more "generic" from Accupro, pricing is more affordable. But ZrN for our applications is far superior.

Helical sells them for about $50 through our distro. MSC sells them for $85.
https://www.helicaltool.com/products...are---35-helix
https://www.mscdirect.com/product/details/65250193

What are these "legendary" discounts?

IMO helical are better anyways, as far as tool life and performance. But we were paying asking price at MSC for our tooling so that may be a factor in play

Sorry, the "legendary" was supposed to come across as snarky. MSC is notorious for marking up everything they sell, then having "sales"

edit: interesting you linked that endmill from MSC, was just buying some stuff and noticed there is roughly a $30 price increase for 1 1/4 LOC vs 1 LOC!