Stelite Question.

[Raoul Duke]

Hi, I dont usually come here as i Know nothing about making Knives.

I'm a collector, but I've now got about half the Production Knives I wanted and i'm spending to much £$£$ on Knives so i thought i'd try to make some of my own.

I work in the Offshore gas industry and part of my job includes changing parts of control valves.

I have on my desk a stelite bar about 10- 12 inches long ,( its longer but about an inch and a half is threaded at one end and the other end has been machined in to a valve plug (looks like a very Tall pointy Mushroom.)
The main body or Valve stem is It is 7/8 of an inch in diameter.

I'm not sure if it has been Heat treated or anything like that to make it harder but i dont think so, (I have also got a friend who used to work were they are made so he can tell me what they do to them when i see him. I think they are just machined)

The Problem here is that the High pressure liquid or gas with sand intrained in it tears them to peices, so in about six months or so I will have been through about 4 to eight of them.I have been using Ceramics recently becuse they last longer, but if you get a Big bit of sand in between the plug and seat the ceramics snaps so we still use both kinds.

I had previously thought it was a lod of sh!te but I see some very expensive blades made from stelite so i got thinking maybe it is quite good as it can throttle Gas or condensate at 90 bar ( about 1300 Psi ) down to nothing with loads of sand in it through a tiny hole it must be quite tough.

So can somebody give me a simple list or break down ( i dont want a complete explanation, although that would be nice, just a list of each step in the process shoud start me off.) of how to turn a bar in to a blade if poss, and i'll start collecting them and reading up on each step of the process.

Cheers
Raoul

[keith_beef]

Google is your friends, Raoul

Stellite seems to be a high cobalt, self hardening steel (air-cool, no need to quench).
From what I've read about other self-hardening steels, they are generally nigh on impossible to anneal; so once you've got hold of an already hardened piece of material, there's not a great deal you can do with it.

http://www.hightempmetals.com/techdata/hitemp6Bdata.php
http://www.mnsaw.com/stellite/aboutstellite.html

Stellite, however, seems to be not particulary hard (often seems to be around 47 to 55 Rockwell C), but is very tough and resistant to abrasion.


KKK.

[one_rod]

I have used quite a few stellite twist drill bits. They are mainly used for drilling hardened steel.
Their main advantage is that no matter how hot you get them they do not lose their hardness.
The "normal" operating temperature is glowing bright red!

I would think that annealing or forging would be just about impossible with any kind of equipment available to the amateur.
Even sharpening them was difficult enough, having to be ground very slowly on a green carbide wheel.

I bet a stellite knife blade would hold an edge forever, but making the thing in the first place might be more trouble than it was worth.


one_rod.

[narsil]

its also used to line the bores of heavy machineguns...which should give some idea of its properties.

[Stuart Ackerman]

I have ground a 4 mm flat bar of Stelllite 6K. It takes forever, and about three times the belts, that I use for 440C. BUT, it is tough, holds an edge for a LONG time, and I sharpened it with 600 Grit diamond Ezelap plates. Steve Schwarzer in the States has forged Stellite, and won't do it again in a hurry!!! You have 2-4 seconds to get one hammer blow, and then you heat again!! Fun, fun, fun ?
It you bend it in use, it can tear off, not snap, but I guess in normal use, that will not be a problem.

You could always weld it onto a s/s blade, as an edge, as I have done. Works well, and if you etch with ferric cloride, the edge stands out well!

Raoul, if you ever send one my way, I could exchange it for some Kydex.
Try something with what you have, even grinding a chisel tip on one end will show you the edge holding capabilities.

Stu