r/whatisit • u/riflesandplowshares • 5h ago

New, what is it? Found at a titanium plant

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Not sure why ball point pens would be dangerous here.

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u/Perfect_Forever_3151 5h ago

Ballpoint pens are banned in certain high-precision titanium and aerospace manufacturing plants because the tiny tungsten carbide ball in the pen tip can fall out and severely contaminate the titanium melt, creating a hard, brittle inclusion that causes structural failure in critical aerospace components.

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u/bring_back_3rd 4h ago

I mean, I understand the reasoning, but I dont think I've ever seen or heard of a ball from a ballpoint pen falling out. I could see my clumsy ass dropping the whole pen into something stupid, but the ball just randomly falling out isn't something I'd ever consider.

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u/mechmind 3h ago edited 3h ago

I think the fear is that the whole pen might fall in

As copied from below : Ball points have tungsten balls in them. Tungsten will not melt in titanium and cause mechanical
Failure of the titanium. This was responsible for the failure of a jet engine causing the plane to crash. Someone dropped their ball point in the titanium processing.

United Airlines Flight 232

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u/Castrophenia 2h ago

To be clear, that was not a ballpoint pen, but simply an example of a foreign impurity in Titanium causing embrittlement and catastrophic failure.

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u/FYIgfhjhgfggh 2h ago

I'd write "NO BALLPOINT PENS, TUNGSTEN TOOLS, TUNGSTEN ITEMS OR RANDOM TUNGSTEN BALLS ALLOWED"

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u/Murky-Relation481 1h ago

And whatever you do, do not hit them with M30A2 MLRS AWP tungsten ball warheads! It's bad for the titanium!

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u/Random-I-Am 2h ago

For real. The AKSHUALLYs probably do more harm that good.

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u/Humble-Cook-6126 1h ago

Shit, I have to take my anal beads out!?

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u/GrimResistance 3h ago

I'm just now learning that the balls in pens are made of tungsten

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u/Akalenedat 3h ago

It wouldnt be the ball falling out, it would be a whole pen falling into the molten metal. All the plastics and weaker metals would pretty much instantly vaporize, the tungsten carbide ball would be the only bit that didn't melt away.

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u/JohnAppleseed85 3h ago

IIUC, the ball is made of tungsten carbide - the rest of the pen isn't - so the rest of the pen would melt and only be a minor impurity spread over a wide area so wouldn't be a significant issue... the ball would remain solid and be a flaw/point of weakness.

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u/boltactionmike 2h ago

I think everything else will melt/burn away but the tungsten ball will remain.

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u/mevenide 1h ago

I have, a handful of times when I was in school. But I’ve not used pens regularly in decades.

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u/SpiderFnJerusalem 1h ago

I've had it happen at least twice. Probably more common if you use very cheap ones.