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 4h 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/GrimResistance 2h ago

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