crystal head pins

Regarding the 46-372 Swarovski crystal head pins:
I do not believe there is a good, safe way to harden them.

They are made of a fine-gauge brass wire, then plated.
This fine gauge allows them to fit through most beads, even some sizes of pearl beads. It also makes them soft and easy to manipulate. The disadvantage is that if it easy to bend into the shape you want ... it is also easy to bend back out of shape.

For this reason, you might want to make the top loop into a wire-wrapped attachement (I'm looking for an image to link in here...), which is more secure than the basic eye pin loop.

However, one method you could try, is work-hardening the portion that is bending too much. With a chasing hammer and a small steel anvil, you could hammer the portion of the wire that you want to harden.

As a side-effect, this will flatten the wire, so be sure to string any beads you want, beFORE you start to hammer (unless they have a large enough hole to string afterwards).

Basically, this compacts the atoms, and that is how it makes it stronger. However since it also changes the shape of the wire (you are changing it from round, to flattened) it will damage or otherwise affect the plating of the portion you are hammering. Depending on how & where it is going to be used, that may or may not be a problem. Since the wire is soft, be sure you don't hammer too hard and squash the wire paperthin. It will probably take a bit of practice to find the proper pressure.

--Polly