You

[TomHChappell]

Are we interested in a bit perspective on the pin discussion?
In my native Swedish, I readily distinguish between these:

I'm not Swedish and don't speak Swedish but I'll answer anyway in my 'lect of English.

"Knappnål" ('button pin')

Straight pin.

"Häftstift" ('fastening tack')

Tack.

"Säkerhetsnål" ('safety pin')

Safety pin.

"Synål" ('sewing pin')

Needle.

Any other pin-like object is a "nål".
What about other Swedish speakers, or speakers of other languages?

I don't know whether there's a good answer for my 'lect of English.

[Chargone]

pin (or possibly sowing pin if i had some reason to make a distinction) - i make no distinction between the ones with the little balls on top and the ones without

drawing pin (though i'd know what someone meant if they refered to one of these as a thumbtack)

saftey pin
needle

the other set is
badge (safty pin on the back basically, right?)
... no idea... bottle cap of some sort maybe?
and i can't tell exactly what that last one is... is that the sort with the spike that goes through the cloth and some sort of cap that covers the point on the other side so you don't impale yourself on it? don't think i have a word for those, really. too much like jewellery to be a badge, usually...

[Tropylium]

Finnish, FWIW: nuppineula ("knob needle"), nasta, hakaneula ("latch needle"), plain neula.

[Skomakar'n]

Are we interested in a bit perspective on the pin discussion?

In my native Swedish, I readily distinguish between these:

"Knappnål" ('button pin')

"Häftstift" ('fastening tack')

"Säkerhetsnål" ('safety pin')

"Synål" ('sewing pin')

Any other pin-like object is a "nål".

What about other Swedish speakers, or speakers of other languages?

I use these names too, but I had actually forgotten about knappnål, so I probably would have said nål for that one as well.
The annoying thing about calling the second one häftstift, is that this is also a häftstift:



I had to take this picture myself, as I couldn't find a single picture on Google using this as the keyword, though, or even by dividing it into häftapparat and stift, which makes me wonder if everyone calls them this. At least my friend across the table, who's originally from Stockholm and now lives in Valdemarsvik in Östra Götaland does too. I did find a few pictures of pins like the following, which I would not call häftstift myself (I don't really know what else I'd call them either, though):

[finlay]

That's a staple; quite resolutely not a pin.

[Cathbad]

That's a staple; quite resolutely not a pin.

In Slovene, both this and "safety pins" would be called sponka (although safety pins can also be called zaponka, which staples can't).

[Ulrike Meinhof]

I use these names too, but I had actually forgotten about knappnål, so I probably would have said nål for that one as well.
The annoying thing about calling the second one häftstift, is that this is also a häftstift:

I'd be inclined to call that a häftklammer, although that applies mainly to these related, but dissimilar, objects:

[finlay]

those are the same things

[Ulrike Meinhof]

those are the same things

No, the first ones are used in these:



And the second ones in these:

[Bob Johnson]

... still the same things

[cromulant]

Yeah, they're both staples. The top one is what I'd call a "heavy duty" staple. The bottom one is just a "staple." If I were contrasting a staple with a heavy-duty staple, I'd probably use the modifier "regular."

I definitely don't conflate staples with safety pins. They are completely different types of fasteners, in both their target and method of application.

[Skomakar'n]

That's a staple; quite resolutely not a pin.

I know, but in my native tongue, these have always had the same name for me and everyone I have ever heard speaking of any of the two.

häftklammer

This I have actually never heard.