Leaf springs are made of damn fine steel, and there are a lot of them out there. You can't find a finer, more readily available source of metal for making knives, swords, crossbows, axes, etc.!.
what I pick up at garage sales & such when I see them - old hedge clippers - the ones with the big wood handles and thick solid steel blades .... not just good steel for making other things - the blades are almost ready made for a damn impressive & formidable thrusting spear point - even have a tang bilt in that's ready for inserting into a heavy shaft ....
Making a knife from rusted scrap metal oddments; https://youtube.com/shorts/hiJc5hSjgIQ?si=SSWSwmUY4iTcV0MP