Once a knife blank is cut out of a circular saw blade, does it need to be heat treated (annealed) or is it suitable to make a knife from it as is?

depends on what kind of blade it is
anything with carbide tips usually does not make a good knife
are u using saw mill blades
most blades of good quality will need to be annealed  ( softened) to drill and install pins
with standard drill bits but the handle portion can be softened without doing the whole blade
check the hardness of the sawblade with a spark test
touch the blade with a grinder and if it makes sparks very similar to a 4th of july sparkler
it is probably suitable for a knife
and if kept cool while cutting out and grinding
may be usable like it is
there are a lot of veriables when dealing with unknown types of steel
post some pictures of the blade and keep asking
questions and we will be more than happy
to answer them to the best of our ability
thanks
kevin

I've already cut the blank out of the blade.
Yes, it was a carbide tipped blade and read nickel/chrome steel.
I've already touched it up on the grinder.  It made sparks of course, but not anything real colorful like a sparkler.

i have tried the nickel chrome blades  on a couple different occasions and have not had any success the stuff will get hard  but also seems
like bubblegum and will not hold an edge

kevin

I had the same experience with a saw blade, I thought it was hard until I went to use it and it bent like a tin can. I assumed it was something I did since it was my first try at a knife. I took the whole knife to non-magnetic and quenched it and I am sure that was the problem if I had only heated the handle enough to drill it maybe it would have worked. Good luck with the knife I hope it works out for you. Jason