Hatton Gardens

[Doug MacQueen]

Well I done some searching and found out a couple things. First being that Robert Mushet added tungsten to a steel mix in 1868, thereby making it harder. Second, tungsten carbide was first used in Germany in 1890. So it is possible a custom made TC tipped 4 inch hole saw was used in 1892. From what I have found so far, silicon carbide grinding wasn't yet used, but diamond grinding could have been used to machine the TC. That 1892 drill rig certainly wasn't built for speed but it can apply the needed pressure to cut efficiently. I also found that Chubb was adding chromium to their steel in 1893.

[Huw Eastwood]

I've found another twist claiming Henri Moissan developed the first two grades in Paris between 1896 and 1898 while attempting to produce the first artificial diamonds. He's famous primarily for his electric furnace which must have come in handy, as Tungsten itself has one of the highest melting points at over 6000 degrees F.

This is the earliest mention I've found so far, with most still pointing to Germany with Osram and Krupp's in the 20s.

Personally I'd be amazed if they could have produced effective tools within such a short time of discovering the initial compounds. The processes and refinement it took to make these early compounds and ceramics useable is a lot more involved than those of the steel industry.

The whole Tungsten and Tungsten Carbide thing is so mis- understood these days, even more so since the low cost tooling and ceramic jewellery arrived on the scene. The metal gets referred to as the carbide, the carbide referred to as the metal, the sintered ceramic confused with the metal and with countless other similar ceramics and so on. I have a stub of 20 mm diameter Tungsten bar which I'll post when I can. It's the dense alloy used as an alternative to depleted Uranium and weighs only a fraction of a gramme less than pure gold bullion. People think Lead is heavy, you should feel this stuff! It's the much rarer metal alloy though which is why it's so dense, and not the ceramic compound derivative. Very expensive and very hard to get hold of. I asked the supplier if there was any chance of a small slice of depleted uranium but he just said 'Now you're being silly..' Was worth a try.

anyway I'll keep looking to see what else comes up. I have a reprint of an old book somewhere 'Procedures in experimental physics' which I think is from the 20s or 30s, and can remember Tungsten is widely mentioned and used throughout its pages. Plus my dads got a prized set of encyclopaedias which are definitely from the 1920s, so I'll have a look and see if there's any mention. Sometimes the info on the net gets a bit vague and clouded up so some good old fashioned paper reference has got to be worth a go.

[Chubby]

I wonder if the welded stellite being harder than the bar is due to the heat inherent in the welding process. Maybe stellite is an air hardening steel.

[Huw Eastwood]

Yes it could well be, those hard facing compounds have some wacky characteristics, I used to use one a long time ago which could only be deposited in a single layer, but the one I'm still using can be built up like Stellite and the heat from successive layers has no effect at all. Thinking of it, I also had some a long long time ago primarily for impact resistance over abrasion and they were a nightmare to deposit and acted different again.
Dread to think how much a big box of Stellite rods are these days, I think They still use it for building up the lobes of worn racing cams.

Heres the prized remaining stub of Tungsten bar. It's 95 percent Tungsten with the other 5 made up of Iron and Nickel. As you can see it's only as thick as my fingers, but it weighs almost three quarters of a kilogram! It sure is amazing stuff.

[Chubby]

Tungsten is seriously heavy. Excellent for making good holes drilled in doors.

[Huw Eastwood]

Tungsten is seriously heavy. Excellent for making good holes drilled in doors.

You'd need your own refinery and factory, that bar works out about £20 per inch!

[Huw Eastwood]

The International Tungsten Industry Association's website (yes there is one, I'm not making it up) has a small section on history, and mentions the early additions to steels and carbides.
I'll try and post a link, hopefully it works..
http://real.itia.info/history.html

[Doug MacQueen]

I think that reference of Chubb using chromium was found in article in The Strand magazine printed in London in 1896. Mushets use of tungsten should be an easy one to find and is most likely the referred to in the ITIA history. I will try to find the German TC article again. If the Swiss could drill a tiny hole in an aluminum oxide watch bushing with diamond coated drill in the 1850's, it is not so far fetched of what could be done 40 years later. The amount of discoveries and advancements in science and industry during the 1800's boggles the mind the more I read about it. Check out the 1800's editions of the Britannica and other encyclopedias. The fact the ITIA went back as far as Agricola is impressive but I am not convinced they have the whole story. Look at us, struggling with how our own trade did things in the 1800's.

[Doug MacQueen]

Well if nothing else I have found that I can make my own TC at home. The temperature required does not need to melt the tungsten as it remains a solid in the process. Only the binder needs to be melted.

[Doug MacQueen]

It should be noted that the 1920's development of the TC dies is referring to the "cemented" tungsten carbides. It was found that in certain tungsten steels, tungsten carbides can occur within the steel alloy. The earliest references found so far regarding that have been from 1904 and 1907.