Here is a lock I made.
This lock was featured in a book by Denis Frechette and Bill Morrison titled The New Spruce Forge Manual of Locksmithing.
It is a very nifty book and I am quite a fan of Denis Frechette's work as well as his youtube videos which I find myself constantly watching even though I've seen them countless times.

The body of this lock is made up of 5 components. 3 of the 4 components are visible, one is internal. The internal piece is a washer with a square hole to accept a shank that acts as the actual locking mechanism that fits into the notch on the shackle.

A lot of the body of this lock is made up of pieces brazed onto the main pipe. The pipe was made from a piece of sheet steel that had been cut in such a way that it could be curled into a sort of cone shape.

I used plain copper wire to braze the components together. I wrapped the wire around the parts where there was a small gap so that when it was hot the little gap could suck up the molten copper through capillary action and make the brazed joint. Borax was used to allow the copper to flow better.

This lock works very nicely.