I made my first knife when I was 13. Crappy photo made long time ago:

The blade made from broken saw that was used to cut the rail tracks (67 HRC maybe?). Ash-wood handle, wrapped around by "paracord", all reinforced with a metal clamp. Sheath made from heat-shrink tubing.
During 20 years (I'm 33 now) of cutting, carving, throwing, wire cutting etc. I replaced the handle 5 times or more. But the blade is still the same one, indestructible. Finally, I embed the handle into rubber bike grip using plenty of epoxy glue and wait 10 days for hardening. I also reshaped the blade a bit. Here it is:



I know, it is not perfect, nor beautiful. Big handle and small blade looks silly, but its extremely convenient. I cuts everything: bones, nails, wires, still sharp enough to cut meat. Steel is not rust-proof, but I like its natural darkish colour. And it serves me soo long (ok, there was some gap for Vic Forester

)