Hi,

My old friend gave me a bundle of HSS square blanks which he was going to throw away.

Between those I have found 2 unusual bits. They didn't rust, they are non-magnetic and they have written on them Stellite 98M2.

I was looking on web and found that such blanks are in fact quite expensive, comparing lets say to HSS.

What they are good for?

Apparently not as hard as ordinary HSS but work well even when red hot.

On my lathe it is unlikely that tool is going to turn red hot anyway.

So what they are good for?

Finishing cuts because they are not difficult to mirror – polish?

Bearing scraper blade for the same reason as above – easy to mirror polish what suggest good quality of blade?

Parting off (assuming I first slice and then grind them (have diamond saws)?

Internal threading bits (can be brazed without loss of hardness).

Any other ideas?

Edited By Martin Dowing on 21/10/2020 19:09:54

@SillyOldDuffer,

Yes, it is good idea not to waste these on jobs where HSS would do te trick.

My observations of surrounding world are telling me that economic collapse now pending may bring a very bright future to those still capable to operate manual machinery and some non carbide tooling.

CNC is great but without cad file is not suitable for making an odd part, neither it is of much use in repair jobs.

Somehow I think that while our civilization is going downhill, we will surely enter recycling era and engineering is going to get new lease of life. Hopefully those who can recognize stellite will get out of social security at that point (if only still alive and fit…)

@Rod,

One time I have made myself in.

Have offered one guy to repair housing of ball valve in his pump by drilling out damaged bit and inserting a proper one "which will never wear off".

So I have taken a piece of 316 Stainless, cut out few short bobbins, made recess with drill and countersink and then welded in Stellite (You can buy cobalt/chromium/vanadim/tungsten alloy in form of welding sticks).

Next part of plan was to turn it to shape. This was already problematic. HSS have failed (despite of welding rod specifications of only 40 HRc, standard carbide struggled but have managed.

Then I had to drill hole through this stellite. Here HSS-Co did work but bits were getting blunt one after another. I could drill about half way (few mm) but next few mm I had to drill with resharpened drill. Failing that material was somehow work hardening and then nothing would drill through. Carbide drills were tending to brake in it btw.

Finally housing for ball had to be cut. Only high grade carbide mill could do it and I have damaged one in the process.

So job was done and these valves (with silicon nitride balls now installed) are working very well for years, but at the end I have subsidized my customer.

When he has asked me to repair other pumps for his company specifically in exactly the same way like first one was done (he was obviously impressed with performance) I gave price 10 x as high as for the first one.

Sadly he didn't come back, though he was phoning few times attempting to get lower price.

Edited By Martin Dowing on 23/10/2020 20:57:54