This big hunk of metal found near some train tracks:

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"Slag from a thermite rail weld would be my guess."

"Totally this. They welded the tracks near where I used to work and there was tons of slag left behind. They were collected in square pans on each side of the weld."

This pair of heavy metal legs that contain screw holes:

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"Vintage school desk frame."

This giant brass key that belonged to someone's grandfather:

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"Found it! It's an ADT Type W Watchman's Key for an 1180 Watchman system. They would do the rounds, and the key would fit into systems to ensure that the watchman visited all the waypoints on the route."

This conical metal item that was found on the shores of the Black Sea in Istanbul, Türkiye:

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"It looks very similar to the nosecone and structure on the ramjets for a Russian KH-31 missile"

"While nowhere near as rare as it once was — it used to be called 'unobtainium' by engineers — titanium is still pretty rare for anything but fighter jets and sporks. (Yes, I know titanium is used for other things; I was trying to be funny.)

That said, wash your hands. Some of the materials used on fighters these days are hideously carcinogenic, and it says 'don't touch' right there."

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"Base of an old torpedo bottle!"

This hard string with two oval-shaped kernels attached to either end:

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"It looks to me like the anther and filament parts that make up the stamen from a fake flower. The string would be folded in half so that the 'kernels' are at the same end, and the part with the red stain would be at the bottom of the inside of the flower. The red stain makes me think that the petals were red and the dye has run."

"I can confirm that’s exactly what this is. My mom used to yell at me all the time for pulling these out of her fake flowers. I used them as bolas for my action figures."

This inch-long piece of metal found on the beach:

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"The remains of the jacket from a 1" Nordenfelt projectile. There was originally a steel core held in that brass cup. The idea was that it would punch through boat hulls, and the brass part was to engage with the rifling of the gun. The gun itself is pretty weird and very old (1870-1890). You fired it by cranking a lever back and forth. It was widely used, too."

This metal device found in central Kentucky:

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"It's a mouthpiece puller for brass instruments. Looks like it's missing a piece on top of the center screw."

"You are absolutely correct. I looked up what that looks like, but modern ones are much simpler designs using fewer but precision-made screws. However, I found one on this page that's very similar in shape and concept (but made of metal) called a Ferree's puller."

This tray made of paper pulp the owner believed was related to embalming:

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"It's a cranial cap. You put it under the head to absorb leaking brain goo."

"You would place that on the pillow of a casket for someone who has had a cranial autopsy done (removal of the brain). It is to absorb any liquid that may seep through the sutures used on the scalp. Better in this than all over the pillow because it would most likely be blood. I've been a mortician for 40 years."

"Funeral Director/Embalmer here. Agree with the other posters. Could be wrong, but this one looks used. Would not recommend touching bare-handed. We use numerous chemicals that an alive person should not touch directly."

This metal wind-up device found in the crawl space of an old house:

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"Looks like the drive mechanism to an antique toy car."

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"Looks like the handle for a dust mop."

This cast-iron device mounted to a wooden base that spins and chops down:

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"I know this one; it's a Victorian-era food chopper! I know it from this video. I think yours is the same manufacturer as in the video, the now well-known measuring equipment maker Starrett."

This spring-shaped piece of metal with a pointy tip:

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"Spiral poultry lacer."

This yellow, hinged piece of plastic found in a sewing kit:

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"It's used to attach jeans buttons. The button goes on one side, and the rivet pointy thing goes on the other, and you snap them together."

This wooden thing with a particle board "blade" and hollow drum found in a thrift store in Pennsylvania:

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"That's a Tremulant (aka vox humana) for an old reed organ."

These two metal rectangles, one with a blade and one with an indented side:

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"It's a magnesium fire starter, but the flint rod has separated from the magnesium and is missing."

This 23" long, hollow metal tube with a connector of some kind:

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"A part of a helicopter rotor?"

"It is definitely this. The triangular part is used to affix the blades, and in the middle is a spring assembly that absorbs the forces and allows the rotation of the arm. Probably from an Alouette 2 or 3."

This small bendable item with one adhesive side:

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"Bendable/adjustable cable manager."

This little tiny pocket on the back of this shirt:

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"It's a vestigial device deliberately installed into a great number of imported shirts so that they classify as a specific article of clothing which avoids a tariff."

"It’s called a ‘nurse pocket,’ and it’s there for reasons others commented."

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