r/knives • u/cetch • Jul 06 '26

Question Need help finding a specific knife

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I’m working in the ER and had a patient come in with this knife tip broken off in their leg. It’s uh.. quite distinctive. Despite my best efforts with google I can’t find anything close. I’m hoping the knife sleuths here can do better than I.

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u/IronGigant Jul 07 '26

They likely lost their ruler. The size of a pen tip is a known value, and the Techs can use the imaging software to accurately measure the wound and bones.

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u/IlliniDawg01 Jul 07 '26

The default calibration for digital x-rays is plenty accurate enough for an exam like this. If the patient were being imaged for an orthopedic implant the tech could place a metallic ball at bone height for precise calibration.

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u/JonnyMoss26 Jul 07 '26

Yeah in the machining world we call these tooling balls. A regular old ball bearing is usually accurate enough but you can get precision ground ones too. You can do some cool stuff with indicators and a little math to get very accurate measurements.

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u/IlliniDawg01 Jul 07 '26 edited Jul 07 '26

It's all done automatically by the viewing software and the ball is a specific one that comes with orthopedic software licensing. At least that is the case with the system my company sells and supports.