1095 is not usually leaf spring. If you are looking to make a knife out of leaf spring, my best advice is to buy some steel that you know what it is and then will know how to heat treat it correctly. Leaf springs from unknown are a gamble. Steel like 5160 is not costly and makes a great knife. There is no test that I know of (that can be done in a simple shop) unless it is sent off to a company. Also, 1095 is not an easy steel to work with. 5160 is great to work with and what many ABS members use for there test knives to become a journeyman. If you just want to make a knife out of unknown steel, cut a small piece and heat to non magnetic and quench in water and see if it will harden enough to make a file skate over the surface and then see if it will snap, or chuck it in the vice and hit with a hammer and it should break easily. Hope this helps.
