Hey guys, thanks for all the replies! I've been off grid for a few days (Las Vegas!!), so haven't responded.
Here's a few thoughts and questions regarding all the responses:
Angle iron for sights:
I thought about that, but thought that the rear, raised sections of the sight I wanted to build at the time might be thicker (in length) than you can get in angle iron. Frankly, never looked at angle iron. I suspect it would be great for most sights, might not for the one I had in mind.
Adrie, I really like the idea of using a bolt like you showed! Saves quite a bit of filing, and bolts are cheap!
Pukka,
I have some farm scrap in my yard as well. Not that much, and the one I pulled hoping it was iron was definitely not! Hence my question about milder steels. I will save the scrap steel I have for something that needs to be hard steel.
Question about tow worms:
I always thought these were separate and distinct from ball pullers, and just served as a way to carry a wad of tow down the barrel. Am I wrong? The posts saying that various steels were not hard enough for tow worms has me confused. If it only needs to carry tow, then why does it need to be strong? As long as it doesn't break in forming, then I would think that any strength metal could carry tow. What am I missing? Are they in fact dual purpose: tow worm and ball puller?
Cheers,
Norm