Tapping Hastelloy - kinda OT

[Nominal]

Anybody with actual experience tapping Hastelloy X? I need whatever knowledge you have on this.

Here's our requirement...

Material AMS5754K ( Hast X )

(1) Hole .1596-.1675 minor dia, depth .36-.40

.1900-32 UNJF-3B depth .25 min

csk 90 deg to .21-.23

 

Tried a couple different things ie. floating and rigid tapping. Different tap styles incl roll tap.

Different fluids. Feeds and speeds etc.

 

Anybody have any suggestions? What is supposed to work on this? I have a couple hundred of these to make so hand tapping isn't very attractive. Thanks in advance for your help. V9 rules! :-)

[Brendan P]

I would try an Emuge Rekord D-ti or rekord D

The ti is coated.These work very well.

Keep sfm under 13

speed 161 rpm feed of 5.035 ipm .

This mtl. is pretty tough stuff.

Hope this helps.

[Guest]

I have tapped Hastalloy C276 before. We used to drill the tap hole for 55-60% thread engagement. We used OSG High spiral taps. I don't remember the exact model. Call you OSG rep. We put trim sol medium tapping fluid directly in each tap hole before tapping. We used a machine with rigid tapping cycle and a floating tap holder. We tapped at 8 to 11 sfm. Make sure you do not work harden the part when you are drilling it. I tapped hast parts for 11 years and found that over time the material was still unpredictable. On some days we could get 20 holes per tap on others we could only get 2. The material would have hard spots in it. Also, call the material manufacturer for their recommendations. I believe Hastalloy is a patented material and is made by only one manufacturer. They also machine the material for their customers. They should be able to help you. I called them once and got some good information. Hope this helps and good luck.

 

[ 01-31-2003, 10:07 AM: Message edited by: Marc Lindsey at San Diego CAD CAM ]

[Guest CNC Apps Guy 1]

Th firs thing I do when tapping high nickel alloys is throw the drill chart out the window. Nickel has a tendency to deform instead of cut. So basically your hole is going to shrink after you drill it then as you tap it, the hole closes on the tap, grabbing it thus breaking it off.

 

So, with that being said, I would run to the highest minor diameter allowable and buy Emuge taps. When it comes to tapping "Super Alloys", you can't beat them. DOn't get me wrong, OSG and other make fine taps, but none are greater than Emuge.

 

JM2C

[Surface]

I havn't tapped the stuff, but I know it can work-harden somthing horrible. As long as I maintaned a good toothload, I had good results.

Good luck

[gcode]

With material that work hardens I've had good results drilling the hole in 2 steps.

Predrill the hole .015-.025 undersize then line bore it to size with a spun down carbide endmill.

This gives you a nice straight hole and eliminates

any workhardening that may have occurred while drilling.

[steve f]

Nominal,

 

I work in a R & D shop and we are machining Hast C276 all the time. My suggestion is forget about tapping this stuff altogether...I had a job that needed alot of tapped holes that were supposed to be dead on center so instead of burning out broken taps or scrapping $500 material we had a carbide thread milling tool custom ground and took about .01" cut per pass with low RPM and thread milled all the holes. Just hit the magic button and walk away without worrying about sparks flying. That's my 2 cents anyway,

 

Steve

[Guest]

I too have thread milled Hastalloy with great success. You might have a problem finding a thread mill small and long enough to do the job you mentioned. But if you can then thread milling is a great option.

[Andy]

I have a job in now that is Hastaloy X and it apparently has 50% cobalt, and Nickel, Chrome, etc. Sounds nasty. I have machined Monel before but this stuff is probably worse. I need to Tap a 1/8 pipe thread 4 places. Good luck to me!!!

Andy

[Guest CNC Apps Guy 1]

ANYTING with nickel in it requires differnt thinking. The higher the nickel content the more difficult it is. Throw cobalt into the mix and YOWZA! That's when it gets REALLY interesting.

 

G-Code's idea sounds really good though. Never tried that. But still stick with Emuge taps.

 

JM2C

[Jack Mitchell]

I liked Bucket’s response immediately and would also tend to agree.

Gcodes analogy is the result of countless hours of dealing with such difficult applications.

 

Not to leave any response as better or worse – I believe the question and answers given on this particularly difficult task puts our members into an experts status.

 

Thank you all, for I have learned something today as well.

 

Regards, Jack

[ROB]

Another thing you can try is peck tap .025 .05

per depth or less lots of coolant,that if your machine can handle it.i do that many times or thread mill if possible.

just a sugeston.

[Guest]

Nominal:

 

Well, did you get the holes tapped? How did you do it? What tool did you use? How many holes per tap did you get? Just curious!!

[Nominal]

Marc and whoever else it may concern,

 

My biggest mistake was thinking that people were following direction. It was a case of "we know we used this kinda tap last time why isn't it working". It wasn't working because my setup man wasn't reading the process instructions, and was using the tap drill for a standard 10-32 tap. With a thread form tap ( roll tap ) the actual tap drill size is about .011 bigger in dia than the largest minor dia tap for a standard. Once I discovered this we never broke another tap. Bottom line is we tapped about 150 holes in Hast-X with a single tap at 500rpm and a fcode of 15.625!!!!. Rigid tapping, using a gh3 cheap xxxx bullxxxx uncoated roll tap and some crappy tapping fluid. Thanks for everybodys advice. Keep the chips flyin and the parts in the usa.

[MACHINEMASTERG]

roll tapped ???ahhh ive had sketchy results roll tapping 316ss and high nickel alloys in the past maybe ill try it again thanks for getting back to us i love to hear the results to the problums asked hear