Can I use a diamond wheel for cutting tile to sharpen my carbide toolbits?

near-necessity

very short period

the touching / grinding

impact and stay sharp ]

down as the cutting arc

better than metals) to the

materials have been developed.

slice through rock and cements...

the host material (the tool)

tool becomes used up?

iron cobalt deposits and

needs to look at this

Well, yes, it's economics. In turning and milling ferrous metals, the costs of using diamond tools can be worked out very neatly from wear-life data that was compiled decades ago. Using diamond cutting tools in chip-making applications on iron and steel is very expensive business, and the amount of it that is due to chemical carbon loss has been quantified. I haven't seen the data since around 1979 or so, when GE was touting its then-new CBN, but it's out there.

There are some places where it's been used on steel. I think it was Pneumo-Precision that was using diamond tools for steel on one of their optical-grade lathes (built on granite bases) back in the late '70s and early '80s. The applications were optical or optical-grade turning.

It's not that it doesn't work, and it's true that there are some rare situations in which it's the way to go. But not in general.

Grinding, honing and lapping are another matter. The same principles apply but the dynamics and the economics are different. Again, I haven't kept up with this. The last thing I remember was some data from Sunnen on their plated-diamond, one-pass honing tools that came out in the early '90s. It's a bit more complex than the situation faced with chip-making tools.

-- Ed Huntress

slice through rock and cements...

the host material (the tool)

The host material isn't where the diamonds are mounted. There's usually an alloy that becomes the bonding agent, and it doesn't have an affinity for carbon. There is no transfer of carbon for that reason.

tool becomes used up?

With grinding wheels that are dressed by diamond, the diamond gets dull and ceases to cut easily with prolonged use. If you're familiar with dressing grinding wheels, you understand why the typical diamond dressing tool mounts the diamond at an angle instead of at right angles. That way, all you have to do is rotate the diamond slightly to present a sharp corner of the diamond to the wheel so it cuts cleanly instead of burnishing the wheel. It would be much the same with diamond grinding wheels. The slightest dulling by absorption renders the diamond far less affective. The diamond may not be used up, but it gets dulled to the point where it takes considerable pressure to get it to cut, and you risk tearing the diamond out of the matrix as a result.

iron cobalt deposits and

needs to look at this

Martin, I think you're overlooking the fact that well drilling takes place at much lower speed, so low that the critical temperatures are never approached.

I'm not convinced anyone is suggesting diamond can't be used for cutting ferrous metals, but there are inherent hazards involved, one of which is the shortened life of the tool, especially if it's at accelerated speeds. The lesson that's important for the home shop types to learn is that diamond grinding wheels should never make contact with iron or iron alloys at high speeds in order to preserve the diamond. The slightest contact affects a wheels ability to cut. So much so that the wheel often requires a dressing in order to restore a wheels ability to cut freely. I'm sure wheel loading is a part of the reason, but dressing the wheel takes life out of it, so it's a good idea to minimize dressing. You can do that by avoiding grinding steel.

Harold

I've actually had occasion to talk to the Kennametals folks who make things like cutting tools. They also produce fine (micron particle size or thereabouts) bronze powder. This is an alloy of copper and tin which is specifically used as a sintering binder for that application - bonding diamond particles to steel tooling.

Jim

I thought that drill heads are continously pumped full of drilling mud, to carry away the cut material. Because the drills run immersed in water-based solution I bet the chemistry is a lot different at the lower temperatures.

Jim

That matrix is the make or break part on diamond blades for "stone" . If its too hard it won't cut jack shit and too soft and the blade is down to the steel in no time.

I cringe at the thought of replacing blades to the point of testing them on the spot. Some times they just sugar coat them and work great for a couple of jobs and then just stop cutting at the worse possible moment. Some won't cut the first tile. Bet I could find about 10 junk ones around here that look like they have lots of life left. I've often wondered if there could be a way to heat the piss out of it with out warping it or have it fly apart on the saw to change a screwed up job into something that will work again. Somehow weaken the matrix that was made too hard... Hmmm maybe electricity and acid. There goes that sharpening joke.

Consider a 5000 foot hole - not the deepest by any means. That is 5000 feet of drill pipe above it. Then the heavy drill head of three rotating cutters. The pressure is very high. The temperature is static vary high and is boosted by the grinding of rock with rock. Forced water or fluid is driven down the tube through the center of the cutter (sounds like a mill doesn't it) and the now dirty, grimy dust is forced upward around the sides of the drill tube. I suspect the point contact temperature and pressure is extremely high. Few really know as much of it is protected under patents. Bound to be some in theory books and now the web.

I think the whole issue is cost of tool and what one can do without it. There are very good replacements that can replace diamond.

Martin

Ive pulled more than one string of drill pipe to find the bit melted down because the weight scale on the drilling line was fooked up and a hell of a lot more weight was allowed on the bit than was proper

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

Kind of supprised that the drill bit doesn't include a system for regulating the pressure on the working face of the bit.

-- Why isn't there an Ozone Hole at the NORTH Pole?

Ok - think of the extreme pressure - many, many times that on the surface of earth. Very special capacitors and transistors, resistors..... Pressure and temperature are very high. Then add the drill temp - tough really.

I in another life years ago consulted with a small company Basin Surveys that made tools for deep under ground measurements. Later in life, in the 80's and 90's I worked for Schlumberger in an ATE division - but having degrees in the stuff and knowing what was going on already, I got to talk to some of the tool designers and developers. I was working with them on ASIC devices - to work down hole. The amount of atomic and nuclear physics that goes on during well services is far outside the common thought. Shaped charges nuclear bombardment and then measure the resultant return impulses. Far out stuff really, but brings home the bacon and next well.

Then there is the comm line from tools down hole - while drilling - that measure what is being cut and the speed of cut. It is done with a long wire - the drill stem. Ground is the other connection. Oh this - the real time cutting and measuring - is less than 10 years old - I mean it is really new stuff.

Martin