how critical is heat control?

Nov 23, 2006
ive got some O-1 coming soon and never tempered myself. before now my friend just used a magnet. if i were to use just the magnet, what kind of temper can i expect? the knives will be small working knives, 6" oal. if i need accuracy, how accurate can i get with a small gas forge?
The real question is: How critical is it to you to have reliable, repeatable results.

The magnet, while used by many, is not a terribly accurate method if you're interested in getting maximum results from your material.
Some guys run thermocouplers/temp controllers on their forges, but success with that will be dependent upon the quality of your set up. You want to know how hot your steel is, not just a particular spot in your forge. You'll want an arrangement that minimizes hot/cold spots. This is usually done by shielding.
I'm pretty sure this has been covered in previous threads ....