Negative hollow grind!

[nozh2002]

RosArms continue to amaze me - first I discover this stacked birch bark handle, then find out that this is 110x18 steel - Russian, pumped up BG-42 with Electro Slug Remelting and Vacuum Arc Remelting. But afte more then a year having it I found this negative hollow grind.

Recently I cut drywall and found out that RosArms Edelveis doing this job easy and simple with just two passes while my EDC Yuna Hard II as well as Kershaw Cyclone ZDP189 need 7 to 10 passes. Of course Edelveis is very thin 1/16" and 2/128"-3/128" on the edge. But also I notice that from the very edge up to the middle of the grind this hollow grind actually going thinner then on the edge itself!

If you think about this - there is no friction after edge passes material it cuts! This is like cutting with sharpened steel thread - almost no friction up to the half inch deep. I am not sure was it done this way for this reason - probably it does. But it makes cutting hard targets easy and pleasant. I noticed this first on watermellon - thick knives just ripping it apart not cutting really.

I am not sure is it unusual - hollow grind is pretty popular, but I noticed this on RosArms knives first.

I think this negative gring is even visible on this picture, I never really noticed this before, but you may see in grind reflection that it is looks deeper.

Thanks, Vassili.

 

[hardheart]

interesting, videos and comments I've seen about makers choosing contact wheels show that they choose diameter and placement to make sure the thinnest part is at the edge. I was wondering if anyone did this on knives, kinda like a Marbles Ideal taken to another level.

 

[Moodino]

It's not an unusual grind. I use it for my Outdoorsman. In fact the edge is convex and the hollow, obviously, concave.