first blade with thin steel

[scott.livesey]

as part of a deal I found for some O1, I have one piece 1/16 x 3/4 x 18"(O1 from Starrett). to avoid warp and possible cracks, would it better to profile and heat treat before grinding the bevels? the knife will be a paring knife with a 3" blade. thanks in advance for your help and suggestions.
Scott

 

[rhinoknives]

Scott,
I do all of my bevel grinding after HTment for those reasons and I like the crisp grind too.
Heat is the enemy , so I use fresh belts and dunk after each pass with 1/16" stock. You could make a few Paring & Fillet knives.

 

[LRB]

About once a year I run a batch of thin bladed penny knife friction folders. I use 3/64" x a little over 3" long blades, 01 steel, and grind them before HT. I never have a warp problem with them.

 

[Mark Behnke]

I haven't yet ground any thin blades but would like to do a chefs type knife maybe 1-3/4" wide 7"long something to chop and slice vegys with.

With a wide thin blade do you back it with something when grinding to reduce flex or is that not needed?

 

[LRB]

I don't think a backer would be needed, but I would certainly advise a stress relief heat cycle before the hardening process.

 

[rolynd]

Yes, Stress relieve is advised.
I had good sucess with hanging long thin blades vertically in the HT oven. This minimizes warp by handling the heated blades. They become quite floppy when hot.
Also you have a short window directly after the quench for straightening. I clamp the still warm blade between two flat bar of steel and let cool to room Temp for 15-20 min. This usually results in a perfectly straight blade.
I do most of the grinding before HT because its quite easy to overheat such a thin blade when grinding ,especially the edge and tip area if you are not careful. As said by others , slow speed on the grinder, fresh belt and dunking after each pass will work. Thicker blades have much more mass to conduct the heat away from the edge and tip area - thin blades overheat much more quickly when grinding and its easier to ruin a blade that way.

I once saw a video from the factory of the german brand "Windmühlen" kitchen knifes. They are known for their special ultra thin grinds which are still done by hand. The blades were ground after HT but they did this on very big, slow moving waterwheels.

 

[rolynd]

Found a vid that shows the process, its in german but pics are still interesting to watch. At min 7:30-8:00 you see how thin the blades are ground, he checks the edge flex on his thumbring. The blades are convex ground hence the wobbling motion of the board the blade is clamped to. After grinding the blades are polished in the old traditional solingen way.

[video=youtube;4sfcDHMkLpU]http://www.youtube.com/watch?feature=player_detailpage&v=4sfcDHMkLpU[/video]