O1 Hardness

d37fan

Active Member
I have my first two blades ready to heat treat and am going to have them done by someone else. What hardness should I have them shoot for. They are both Bushcraft style, scandi grind, 1/4" thick.
Thanks for your input, Dale
 
I have my first two blades ready to heat treat and am going to have them done by someone else. What hardness should I have them shoot for. They are both Bushcraft style, scandi grind, 1/4" thick.
Thanks for your input, Dale

Most of knifemaking is finding the most acceptable compromise between two or more properties in the steel. In most cases it is the best balance between hardness (strength) and toughness. In this pursuit problems arise in universal use of steels for different applications. O-1 is one example of this. Each steel will have a sweet spot where you will get the maximum strength for that maximum toughness before the Rockwell hardness lowers strength to the point that all you gain is toughness while losing strength. For O-1 this point is between 61HRC and 63HRC because it was made for high strength, abrasion resistance in applications of slitting and cutting so its chemistry leans it naturally in the strength direction. Thus in order to get the equal toughness of say 5160 or L6 you will need to soften it much more than those steels in order to overcome its natural properties. If 61-63 HRC is a bit high for a chopper so 58-59 HRC may better suit the task but you will sacrifice much of the steels potential doing it. L6, 5160 or even a 10XX series with less than .85% carbon, on the other hand, could maintain a better toughness to strength ratio for the application.

If, on the other hand fine slicing and cutting is what you are after, then go no lower than 61 HRC and O-1 will not let you down.
 
Back
Top