Great knife steel, I used to make lots,100s of kitchen and fillet knives out of old cross cut saws. You need to heat treat it though, it's too soft for good knives in the saw temper. These are most likely 10XX steel where some of the big circle saw blades are L6. With a spark test old cross cut saw throw a 10XX spark (a intense shower of bright sparks) and L6 throws a 01 type spark ( a less intense darker spark)
Don Hanson