# Stellite and other special/unusual tool bits



## Bob Korves (Aug 23, 2017)

Not sure if this is the correct place for this post, not really a tool gloat or anything similar, but I did not see a better choice of where to put it.

As part of a tool lot I bought several years ago, included were some tool bits and blanks that I was not familiar with:


The bits oriented horizontally in the middle, and the single bit on the right, are Stellite tool bits, intended for high heat well above the M2 and M42 high speed steel that is typical in our shops.  The bits in the picture range from 5/16" to 1/2" square in cross section.

The four bits top middle are Stellite 2400.  All I can find on this alloy is that it is Cobalt (37%), Chromium, and Tungsten.  Very hard and tough stuff, extremely high hot hardness.

The four bits at lower center are Stellite 98M2, which I first thought might be just our everyday M2 high speed steel, but not so:
http://www.steel-grades.com/Steel-Grades/Tool-Steel-Hard-Alloy/Stellite-98M2.html
Again, very hard and tough stuff, extremely high hot hardness.

The single bit on the right is Stellite Star J:
http://www.conradhoffman.com/stellite.htm

The two small 5/16" bits on the left are Latrobe Crusader XL.  My cross reference shows that to be T-15 tool steel, a Tungsten based high speed steel. "T' is for tungsten based alloys in cutting tools, "M" like in our M2 and M42 high speed steels is for Molybdenum.  Tools usually (always?) have both, but the dominant one is the class the alloy is placed in.  Molybdenum is used more today because it is cheaper.

The remaining tool to the right of the two small ones is Union 757 "Cobalt Super HSS."  This is from Union Butterfield, and is also a T-15 alloy.

These tools are all tougher than HSS, especially when near red heat, and will cut at red heat.  They are stronger than HSS but somewhat more brittle.  They are harder than HSS but softer than carbide.  You can tell the Stellite alloys even with the writing abraded off, because they are not magnetic at all, zero.  The notches in the ends of the blanks also identify them.  The T-15 tools have a fairly strong magnetic attraction.

Bring a magnet when you are looking at old HSS tooling.  If you find ones that are non magnetic, pick them up.  The Stellite tools are cast and some of them can be quite nasty looking, but are still gems.  All of mine look to the eye smooth and shiny just like HSS, but seem heavier.

These tools are safe to handle, but do not breathe the dust if you grind them.  Seriously.

Time for the (unplanned) gloat:  I probably did not pay more than $1.00 for all those tools.  If you bought similar ones new today they would probably be closer to $500.

Oh, and here is a very good cross reference for cutting tools:
http://www.varcoprecision.com/tools.html
Very helpful when sorting tool lots of old HSS.


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## benmychree (Aug 23, 2017)

Bob Korves said:


> Not sure if this is the correct place for this post, not really a tool gloat or anything similar, but I did not see a better better choice of where to put it.
> 
> As part of a tool lot I bought several years ago, included were some tool bits and blanks that I was not familiar with:
> View attachment 240327
> ...


The notch in the end of the Stellite tools marks the pouring gate end of the tools (they are cast in molds), and the gate end may have defects, so it is marked and the finished tool shape is ground on the end opposite the notch.  Stellite is also used on gas engine and other valve seats and discs, where other materials tend to erode and consequently leak.


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## Ed ke6bnl (Aug 23, 2017)

do you use diamond and or a green wheel to touch them up?


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## chips&more (Aug 23, 2017)

I’m using for the most part, Super MoMax, have a lot of it! Kinda forgot about Stellite! I have that too, but have not used it for a very loooooong time! Thanks for the senior moment reset!


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## benmychree (Aug 23, 2017)

Ed ke6bnl said:


> do you use diamond and or a green wheel to touch them up?


Regular aluminum oxide wheels work with Stellite.


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## benmychree (Aug 23, 2017)

It just entered my memory (or should I say, exited)?  That there is another one of these cast alloys like Stellite, that is Tantung, rather similar in it's uses, but different alloying ingredients, mostly tungsten and tantalum???   Here is a web site with some info;   http://www.tantung.com/


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## benmychree (Aug 23, 2017)

Another site re; Stellite and Tantung;    http://www.conradhoffman.com/stellite.htm


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## ELHEAD (Aug 23, 2017)

I have some Tantung . Have never tried grinding it. What would be good for a grinding wheel?


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## benmychree (Aug 23, 2017)

ELHEAD said:


> I have some Tantung . Have never tried grinding it. What would be good for a grinding wheel?


Regular aluminum oxide will do the job.


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## Bob Korves (Aug 23, 2017)

benmychree said:


> Regular aluminum oxide will do the job.


It may be a little slower than cutting M2 HSS, but you will get there...  Don't forget to wear a good dust mask...

Edit:  Do NOT quench the tool.


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## benmychree (Aug 23, 2017)

Bob Korves said:


> It may be a little slower than cutting M2 HSS, but you will get there...  Don't forget to wear a good dust mask...
> 
> Edit:  Do NOT quench the tool.


It's a wonder that so many old machinists have survived to old age with all the stuff we were exposed to; grinding dust, white lead, triclorethylene, PCBs, and so many other things that modern science tells us are bad, even very dangerous!


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## Ulma Doctor (Aug 23, 2017)

Hey Bob,
i'll offer you triple what you paid for (each) for a few of the bits 

i use stellite insert bladed meat grinder knives in my industry, we sharpen about 120 blades every month.
it sharpens to a fine edge if you have the proper grit grinding wheels


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## Silverbullet (Aug 23, 2017)

Tecumseh engines use to use stellite  in there exhaust valves. I use them for boring bars they're super hard. I think some of the old car valves are the same.


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## ELHEAD (Aug 23, 2017)

benmychree said:


> Regular aluminum oxide will do the job.



Thanks!


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## Bob Korves (Aug 23, 2017)

A lot of aircraft engines used Stellite for the valves and seats of internal combustion engines, and in the turbochargers as well, and in the turbines of turboprop and jet engines.


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## Ulma Doctor (Aug 23, 2017)

briggs and stratton used stellite valve seats on their I/C series engines


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## Bob Korves (Aug 24, 2017)

There are a lot of different flavors of "Stellite" for different needs.


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## uncle harry (Aug 24, 2017)

Silverbullet said:


> Tecumseh engines use to use stellite  in there exhaust valves. I use them for boring bars they're super hard. I think some of the old car valves are the same.



Wisconsin air cooled engines also used stellite valves.


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## Silverbullet (Aug 24, 2017)

Ulma Doctor said:


> briggs and stratton used stellite valve seats on their I/C series engines


That's why there valves burnt out , if the exhaust valve was the same material they wouldn't need the valves cut and lapped. I've had some engines being used a lot that every few years I'd redo the valves . I've also had many of them pop the seats heat and expansion they'd loosen up and pop out .yes I new Wisconsin valves were stelite also many makes used them in some and not others even just exhaust valves. 
But I got tired of hearing how Tecumseh engines were no good . They used pressurised oiling system in all models. People always say they were junk but if they took care of them they'd last for decades.


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## Richard White (richardsrelics) (Oct 2, 2017)

Ulma Doctor said:


> Hey Bob,
> i'll offer you triple what you paid for (each) for a few of the bits
> 
> i use stellite insert bladed meat grinder knives in my industry, we sharpen about 120 blades every month.
> it sharpens to a fine edge if you have the proper grit grinding wheels



I used to work for Stellite in Goshen Indiana, that is where they made the stuff, not sure if they made it elsewhere in the world.. 
I ran the 40 hp Puma CNC Lathe and machined that stuff..  Should have seen the boss's face when I was taking a .250 depth of cut thru the Stellite and base mat'l, (Stainless) in one pass, with a Ceramic tool.  We welded Stellite to base metal and my job was to machine it down to finished size.
We had tried small radius ceramic tools but the kept breaking due to interrupted cuts...
So I put a round Ceramic tool in there and with one pass took at least .250 depth of cut, which was a whole lot more than the reps said it would do... no coolant though, that tended to blow up insert...

The also made the Stellite edged meat cutter blades there on a dedicated welding machine...

Ahh but that was a few moons ago.....


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## crazypj (Oct 2, 2017)

Back in early 60's I remember my father having exhaust valves built up with Stellite welding and re-ground at local garage. 
Took about 20~30 minutes per valve, Joe Morgan wouldn't let us see what was going on. His grandson was still running the place last time I saw him.


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## middle.road (Dec 19, 2017)

As Ben mentioned above, 'exited' memory banks. Memory is such a fleeting thing.
I started out in the tool room and had totally forgotten about Tatung & other Stellite items.
We handled all the perishable cutting tools and such.

So I came across a 3/4"x1"x6" 'Parallel' in my drawer. No markings on it except for the two notchs.
Magnet slide off. It'll probably spend the rest of it's time with me as a parallel.


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## savarin (Dec 19, 2017)

Hmm, just thinking out loud.
Could you use stellite welding rods to place a bead on the end of a chunk of steel and sharpen it for a cutting tool?


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## crazypj (Dec 19, 2017)

I have no idea but would be interested to know. Can stellite be used to machine titanium?


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## rzbill (Dec 19, 2017)

savarin said:


> Hmm, just thinking out loud.
> Could you use stellite welding rods to place a bead on the end of a chunk of steel and sharpen it for a cutting tool?



I would imagine so.  I've been in the plastics industry a long time and a majority of the extrusion screws I have experience with have stellite welded onto the tips of the screw flights (major diameter of thread in machinists lingo) where the screw rubs against the barrel (commonly hastelloy).

While I have seen it chip, it is a rare occation considering the millions of run hrs on over 100 extruders running 24/7 at 500F plus or minus 100F depending on the polymer.

Interesting to see them fabricated.They start with a blank larger than the screw OD, machine a groove in the blank that coincides with the future flight tips then lay the stellite weld into the groove.  The screw is straightened and then machined and polished.  The stellite is essentially invisible after that.


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## benmychree (Dec 19, 2017)

I believe that Stellite cutting tools are for cast iron and non ferrous metals, not steel.


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## Dabbler (Dec 19, 2017)

I have one, lonely stellite tool.  It has worked well in all materials including titanium.  Nice find!


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## crazypj (Dec 21, 2017)

Thanks Dabbler, I have a friend in Wa. who is going to try titanium soon, he'll be interested to know Stellite works.


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## Jimsehr (Dec 21, 2017)

I used to make thousands of stellite bearings out of bar stock. That was in the 60’s and back then the 7/8 dia bars were $ 9600 each. I still have a few parts in my tool box. We used to keep the chips in clean barrels and when we had enough of them we had them cleaned with ultrasonic cleaning at 50 cents a pound then sold them 
back  to maker. One time I had 25  thousand dollars worth of chips in the back of company truck . That was enough to buy a house back then.
I still have carbide file I used to break edges on parts. The stellite would cut a standard file.


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