Lead rivets.

I use lead rivets on many knives I make. They are easy to make any size. I wrap foil around a drill bit of the desired diameter then carefully remove said bit. Clamp one end in a vise grip and carefully pour molten lead in the open end. Let it cool and unwrap. Cut to length, insert, and pound away.

I've also done poured ones. Both work good.

If you are able to use something other than pure lead you can reduce your temps way down. 63/37 solder used for electronics is eutectic with a melting point of 361 degrees or you can go to a stained glass shop and pick up a one pound roll of 60/40 wire solder that would have melting range from 361 - 375 degrees.

I'm not a knife builder so I don't know if you have that as an option or not, just thought I'd throw that info out there just incase.

I have helped salvage a few nice turned bowls that had the bottom turned too thin and the mounting screws poked thru. We turned a dovetail shaped circle where the screws showed and poured in pewter and then turned the pewter smooth. Also pewter has a real low melting point around 330 to 420 and good pewter has no lead in it.
http://www.woodcraftguild.org.au/wp-content/uploads/2012/05/Use-of-pewter-in-wood-turning.pdf

That is good to know.

My well used EK edge and 1/2 has walnut slab handles with the poured rivets and were used I was told when it was made that the lead could be peened to tighten if they came loose. The knife was used by me in the '60s and the pins had an X on each like hit with a screwdriver and were slightly recessed. The blade is still shaving sharp on both sides. Saved now with my USMC K-Bar.