We decided to get in one more test before we test the Shun tomorrow and we decided to go to the opposite side of the world to do it. We sheared off a couple pieces of 18 gauge cold rolled steel blanks in a manageable size (2" x 6").
To the best of our information this material is about B50 (not C, B) on the Rockwell. 18 gauge is about .050" thick. We ground a bevel at 19° using 80 grit ceramic and then finished it with 180 grit ceramic. Removing the burr was a nightmare and really not quite certain if we ever did get it all. (After looking at the picture below more closely, I'm pretty certain we didn't). We gave up when we got an edge that measured 275.
Then we placed it in our Structural Edge Tester and ran 1 set then measured again. So pre roll we were 275 and post roll 818. That's 543 points of roll after only one set. We also began the test 100 points duller than we normally test at so the actual roll rate when compared to our other knives might have been even higher than 543. It was bad and that's close enough for the time being.
So why do we conduct such extreme if not ridiculous tests? To figure out where the fences are. We know something about the bottom of the barrel now and tomorrow we'll know something about, what Shun thinks anyway, is near the top.
To the best of our information this material is about B50 (not C, B) on the Rockwell. 18 gauge is about .050" thick. We ground a bevel at 19° using 80 grit ceramic and then finished it with 180 grit ceramic. Removing the burr was a nightmare and really not quite certain if we ever did get it all. (After looking at the picture below more closely, I'm pretty certain we didn't). We gave up when we got an edge that measured 275.
Then we placed it in our Structural Edge Tester and ran 1 set then measured again. So pre roll we were 275 and post roll 818. That's 543 points of roll after only one set. We also began the test 100 points duller than we normally test at so the actual roll rate when compared to our other knives might have been even higher than 543. It was bad and that's close enough for the time being.
So why do we conduct such extreme if not ridiculous tests? To figure out where the fences are. We know something about the bottom of the barrel now and tomorrow we'll know something about, what Shun thinks anyway, is near the top.