Mike, thanks for confirming that the blades are used with the bevel side up. I am not surprised that the edge rolls towards the flat side of the blade.
The edge rolls because the steel is not able to support forcing the cutting edge into the material to be cut. The cause of this weakness can be seen in the properties of steel and/or in bevel angle and bedding angle geometry.
For work with difficult material the sum of the bevel angle and bedding angle can reach as much as 60°.
The simplest way to correct this issue is to sharpen a microbevel or to regrind the blade to a higher bevel angle, e.g. 35° to 40°.
An alternative way is to use blades made from steel with better edge retention and impact resistance. Blades made from some powered metal alloys remains sharp much longer than blades made from high carbon tool steel O1.
Jan
The edge rolls because the steel is not able to support forcing the cutting edge into the material to be cut. The cause of this weakness can be seen in the properties of steel and/or in bevel angle and bedding angle geometry.
For work with difficult material the sum of the bevel angle and bedding angle can reach as much as 60°.
The simplest way to correct this issue is to sharpen a microbevel or to regrind the blade to a higher bevel angle, e.g. 35° to 40°.
An alternative way is to use blades made from steel with better edge retention and impact resistance. Blades made from some powered metal alloys remains sharp much longer than blades made from high carbon tool steel O1.
Jan