Got Stellite...what to use it for?

[WCraig]

I figured out that I have several lathe tool blanks of Stellite. With my tiny 6X18 Atlas lathe, I'm wondering where best to use them?

In a box lot from a recent auction purchase, there were quite a few tool blanks. At first I thought they were all HSS but when I looked up the name "Deloro Stellite", I found that it is not a steel at all. It has no iron content and is not attracted to a magnet. Apparently these super alloys were developed about the same time as carbide tooling. They can be run far hotter than HSS without losing hardness--up to a red heat!. Carbide can run hotter still. However, Stellite handles shock better than carbides and is therefore better for intermittent cuts that would chip or crack carbide. Stellite can be ground with standard aluminum oxide wheels so no special requirements for sharpening. However, they should not be quenched in water--thermal shock is apparently bad. Wear a mask, the dust is toxic.



All the pieces on the upper left are 1/4" square, 3/16" on the right. The short piece at the bottom is 3/8" and the Tantung G blank is 5/16".



I'm not clear if Stellite holds a sharp edge longer than HSS.

For my shop, I'm not sure what would be the best use. I think using it in a fly-cutter type tool would make sense. It would allow pretty aggressive metal removal at relatively high fpm.

Other than that, I'm struggling. A lathe roughing tool of Stellite might work for others by my little Atlas doesn't have the rigidity or power to hog off deep cuts.

If it does maintain a sharp edge better than HSS, I could see it for threading tools or in place of HSS cutters in boring tools.

BTW, if you like more background on such tool blanks, there is a a good web page at:

Cast Alloy Lathe Tools

overview of new and vintage cast alloy lathe tools

www.conradhoffman.com

From what I read, Stellite tools can be run at cutting speeds roughly twice that of HSS and nearly as fast as carbide. The Blackalloy Company also has some detailed recommendations on tool geometry and cutting speeds at:

Blackalloy Multi Spindle Drill Heads, Tapping, And More

Blackalloy Multi Spindle Drill Heads, Self-Feeding Drill Units. Industrial Automatic Drilling and Tapping Units. Cutting Tools, Drill Unit Components and more.

www.blackalloy.com

Blackalloy Multi Spindle Drill Heads, Tapping, And More

Blackalloy Multi Spindle Drill Heads, Self-Feeding Drill Units. Industrial Automatic Drilling and Tapping Units. Cutting Tools, Drill Unit Components and more.

www.blackalloy.com

Note that new Stellite tool blanks are roughly 10X the cost of HSS!

Craig

 

[benmychree]

Stellite is used mostly for cast iron, and does not particularly hold a fine sharp edge, and roughing that would use such tools is not within the capability of a 6" Atlas. It was developed by the Haynes auto company way back, for cutting tools, and is used for valve seats and wear surfaces, and can be applied with an acetylene torch and machined with harder grades of carbide or CBN. Tantung is a close cousin, containing tungsten and tantalum.

 

[mmcmdl]

We had a nuclear sub job that used stellite as a braking system . It was welded onto pistons and supposedly machined to a given finish with no voids . It's what put Middle***** Machine Company out of business . It was tough as nails but I'm not sure as to it's tooling properties . I would think if you could machine it , it wouldn't be appropriate for tooling .

 

[Tozguy]

I'm wondering where best to use them?

Use them anywhere you would use HSS. The results you get will depend more on how they are used than anything else.
I have been using some Crobalt bits and find that they go longer before sharpening than HSS. If you do not want to use coolant then cast alloy might give an edge over HSS when running hot. To my mind Crobalt bits do everything the HSS bits can do but with an edge that lasts longer when pushing the envelope.

 

[WCraig]

Use them anywhere you would use HSS. The results you get will depend more on how they are used than anything else.
I have been using some Crobalt bits and find that they go longer before sharpening than HSS. If you do not want to use coolant then cast alloy might give an edge over HSS when running hot. To my mind Crobalt bits do everything the HSS bits can do but with an edge that lasts longer when pushing the envelope.

Thanks, that is helpful. I don't have either external or internal threading tools yet. I was thinking that maybe Stellite would be good for that if it holds its shape longer.

When you say "coolant", you mean flood coolant, right? That's not an option for me. I assume you use simple cutting oil/fluid with your Crobalt bits?

Craig

 

[Tozguy]

That's correct, I make a distinction between coolant and cutting oil. I don't use water based coolant (flood, mist or other).
I do use cutting oil applied with a paint brush for most of the steel turning I do with HSS and Crobalt tools. Exception is for aluminum and cast iron where I use WD40 and furnace oil respectively.
I don't know how closely, if at all, that Crobalt relates to Stellite but this info was useful to me.

Crobalt cutting tools

 

[T Bredehoft]

Obviously you have them in your possession, use them like HSS, when they're gone, go to HSS rather than paying the high dollar price.
Stelilte has a lower melting point than steel or HSS, I used to use Steliite for hardfacing tooling fixtures. I'd use it as filer rod, welding with TIG. The tooling then had to be ground with a green wheel.

 

[Tozguy]

I too would advocate the use of HSS and cast alloy over the use of inserts. It means that learning to grind is unavoidable but well worth the time and effort. Carbide inserts sidestep the need to grind but are expensive and involve a learning process as well. Whether it is for choosing inserts or grinding your own tools this article might be of help.

Sandvik Coromant

www.sandvik.coromant.com

 

[WCraig]

I don't know how closely, if at all, that Crobalt relates to Stellite but this info was useful to me.
Crobalt cutting tools

I believe Stellite and Crobalt are more similar than different as they both are Cobalt-based alloys with little or no iron. Hoffman's page that I linked above groups them as Cast Alloy lathe tools.

Your link was really good. They have an extensive comparison of Crobalt to HSS and carbide with advantages and shortcomings explained. For example, they suggest "Cast Alloy is ideally suited for turning tougher materials such as various grades of stainless, cast iron, high carbon steels, and high tensile steels, but unlike carbide where you would need another grade of tip it is also fine on non ferrous materials...". But: "Crobalt is easier to chip than HSS when used in thin sections, so for threadcutting [...] it is better to use CoHSS or HSS bits."

I have a chunk of mystery steel that just about defied cutting. I may give it a go with a Stellite bit.

Craig

 

[WCraig]

Obviouslys you have them in your posession, use them like HSS, when they're gone, go to HSS rather than paying the high dollar price.

I've got both! I've probably got multiple lifetimes of supply of HSS--plus the group of cast alloy blanks I showed above. I'm trying to understand if there are particular uses that really suit the Stellite.

Craig