# Very hard steel



## RogerP (22 Jan 2014)

At the car boot this morning I bought a job lot engineering tools and stuff (nothing exciting). 

Amongst it all are some small bright strips about 2.36mm thick looking like HSS. BUT they are so hard a grinder only just takes a tiny corner off - and that takes a quite while. I've tried three different wheels with much the same result. 

I am fairly used to using HSS but this is much, much harder.

What can it be (does it have a name) and what's it for?


Edit: It's attracted by magnets and grinding sparks are small, few and red.


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## Spindle (22 Jan 2014)

Hi

Some info here re spark testing

http://www.scrapmetaljunkie.com/241/the ... g-metals-2

Nickel or cobalt alloy steel perhaps - do you have a cobalt drill you could use as a comparison?

Regards Mick


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## MMUK (22 Jan 2014)

Red sparks? I would say either cobalt steel or tungsten steel  HTH


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## rileytoolworks (22 Jan 2014)

I agree with MMUK. Either Cobalt or Tungsten, IMHO.

What else did you get?

Adam.


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## Random Orbital Bob (22 Jan 2014)

I know nothing about sparks but it sounds like carbide


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## RogerP (23 Jan 2014)

Thanks for all the input!

Spark testing, measuring, weighing and exercising my rusty arithmetic lead me to believe it's Tungsten Carbide.

The spark test and the weight (almost twice as heavy as HSS) agree with the info in those links.

Dunno what I'm going to do with it though


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## spinks (23 Jan 2014)

Dies it have a rusty surface? sounds like it could be a material we refer to as "hardock" in work, just a mild steel but heavy, and very hard. Used in high wear applications on ships like dredgers and quarry machinery.


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## RogerP (23 Jan 2014)

No rust - looks just like HSS - but it's not.

Almost positive now that it's Tungsten Carbide


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## Spindle (23 Jan 2014)

Hi

Isn't tungsten carbide non magnetic?

Regards Mick


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## MMUK (23 Jan 2014)

Spindle":lo38rl45 said:


> Hi
> 
> Isn't tungsten carbide non magnetic?
> 
> Regards Mick




No, Tungsten carbide is made with roughly 6% cobalt. Cobalt is magnetic so you get a low magnetic property in TC. Tungsten on it's own is not magnetic. HTH


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## Andy RV (27 Jan 2014)

Carbide has very little magnetic attraction, you say the strips are bright? Tungsten carbide is a dull and dark grey colour, it's more likely cobalt.


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## PhillyDee (28 Jan 2014)

Carbide is magnetic, especially the rod. And tool blank carbide is highly polished to mirror finish.

I vote carbide


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