Hastolloy C276 ???????

[shawn]

We are wondering if anyone has any info on machining this material. I have heard this stuff is nasty??? We are going to be turning,drilling,boring,tapping and milling. They will be 8" in diameter and about 1" thick with a bore of about 1". There is also an offset bore that we will be doing on our HAAS so any help with ooling feeds and speeds would be much appreciated.
Thanks
Shawn

[cdlenterprises]

I've never cut Hastelloy before but if it's anything like Inconel it's nasty. Low speeds and high feedrates are the key. For roughing you need to push hard and get the material out before you work harden it. Use the toughest grade and most abrasion and heat resistant coating that you can. Good luck tapping it...can you threadmill instead?

[shawn]

No unfortunatly it's a 10-32 thread. I figured that is going to be a pain!!!

[kalmah]

Originally Posted by shawn We are wondering if anyone has any info on machining this material. I have heard this stuff is nasty??? We are going to be turning,drilling,boring,tapping and milling. They will be 8" in diameter and about 1" thick with a bore of about 1". There is also an offset bore that we will be doing on our HAAS so any help with ooling feeds and speeds would be much appreciated. Thanks Shawn

Turning: I can't give you advice, I'm not specialist of turning.

Milling: Use moderate cutting speed and high feedrates. Don't use standard end mill. There is special end mill on the market design for material difficult to cut.
Drilling: Use drill with internal coolant
Tapping: Euh good luck. Use whirling tool as thread mill. The process is long.
but if the tap breaks, the part is broken... and the price of Hastelloy isn't cheap . If the whirling tool breaks, it's not a problem. You can remove the broken tool without problem and your part is always good.

[Karl_T]

We had to drill a number of somewhat larger holes in this s$%^.

A Raycon drill point http://www.winsloweng.com/articles/g...rm_content.htm
solved the problem.

Otherwise, treat it like 304 only worse. You better bid enough to make some bux on this job.

Karl

[ajl6549]

Hastalloy is made up primarilly of nickel along with molybdenum, chromium and bunch of other stuff so it's tuff to machine but not impossible. I've machined inconel and monel, hastalloy is similar. Iscar, Seco and Carbaloy all make carbide insert grades for this mat'l. (I like Iscar). As for drilling and tapping, there are many companies out that can help. OSG Tap and Die Co. has a tap made for Nickel alloys called an EXOTAP VC-10 Ni. At any rate spend the money for good quality tooling, this will make your job some what easier.

[mxtras]

The only bit of advice I can definately offer is for drilling. For this and other super-alloys that are difficult to even drill - use a drill point included angle of 126.5 degrees with a spiral point and very minimal relief. Try Guhrung drills for smallish diameters - the web on these drills (parabolic) is substantially thicker and yields a far stronger drill than a standard drill. Titex is another brand to try - they have their metallurgy down and make the most durable, flexible, break-resistant drills I have used and they hold an edge well under fire. The Guhrungs are a bit more difficult to grind because of their flute shape.

I was a tool grinder in a massive, Austrian machine shop and developed this information (included angle of 126.5) while attempting to find a way to get more than one drill per hole in a super-tough stainless variant used on catapult systems. This angle allowed us to go from one hole per drill to over 36 holes per drill without re-sharpening.

Long story. You just got the Reader's digest version - condensed.

Scott

[Geof]

Originally Posted by shawn No unfortunatly it's a 10-32 thread. I figured that is going to be a pain!!!

Scientific Cutting Tools ( www.sct-usa.com ) claims to have carbide thread mills covering 2-56 (!!) up to 1/2-20.

[kalmah]

We (our cutting tool company) have solved this kind of problem. The customer use tap on this kind of material. The size is M4. Our customers make 10 holes with tap after, he has to change the tap. We have tried thread mill and it breaks if we machine in one time. Of course it's possible to machine the thread with thread mill, but not in one time.
The use of whirling tool as thread mill isn't longer that thread mill. You can machine the thread in one time. Our customer use now the whirling tool. He (the customers) has win 50% of production time.
Of course your dimension of thread is bigger (approximatly M12). Try thread mill. if it breaks, use whirling tool as thread mill.

If you want more details, send me a private message.