spoonrobot wrote: ↑Fri Oct 09, 2020 7:45 am
H1 also responds very differently to sharpening with different grits, perhaps moreso than other steels. Sharpening the serrations with a lower grit sharpening block/sticks (320 grit silicon carbide) gives a noticeably longer-lasting edge than doing the same with an 800 grit block.
Agreed.
A lot of folks seem to like coarse edges for highly wear resistant steels with lots of carbides, like S110V.
But where I think these edges can also shine is on low carbide steels that are run softer. Think PE H1, AUS8, 8Cr and 1095.
Softer steels roll and blunt more easily than say, K390 taken to the mid 60's. The apex takes less force to deform. Polished edges are only good as long as you maintain apex integrity. When they blunt or roll cutting ability takes a dramatic turn for the worse.
Add some microserrations to these types of steels by giving them a very coarse finish, and even after they blunt and roll a bit, there is still slicing aggression left.
I bet there is someone out there reading this sitting on a PE H1, AUS8 or 8Cr knife they don't use a ton due to lack of edge holding. Try this idea out and see if performance improves.
I ran a lot of infornal cardboard trials with my PE Aqua Salt using a variety of finishes, and that's how I first came to appreciate coarse edges.
I started with the UF stones from Spyderco and observed how long I could slice cardboard. Then the fine. Then the medium. Then a DMT fine. Then a DMT Extra Coarse. Then the diamond rods. Then 120 grit sandpaper.
What I found is as the edge finish decreased in grit, slicing ability was able to be maintained longer. Even if the 120 grit edge had no shaving ability and the ultrafine edge could whittle a hair, the former would keep slicing and slicing while the latter displayed a steep performance drop off once that aggressive bite was worn off.
I think in some ways softer, low carbide steels benefit more from coarse edges than steels like K390, S110V and M390 do. High hardness gives those steels an edge stability softer steels can't match, letting the polished edges maintain cutting aggression for longer stretches of time. If I take a 57rc AUS8 knife to 8000 grit and chop some stuff up on a cutting board, the edge is more likely to roll and deform than 65rc K390 taken to the same finish.
At work I use bargain bin chef knives because I'm not afraid of them getting a little dinged up. They have soft stainless steels I'd guess are around 56rc based on use. I grind their edges with an 80 grit sanding belt and microbevel with the medium sharpmaker rods. Even though I enjoy a higher polish on kitchen knives used at home with harder steels, having the slight microserrations the medium stones offer lets them keep slicing longer between sharpenings. As they blunt throughout my shifts they can still slice a ripe tomato, because a mildly rolled toothy edge still bites into the skin, while a mildly rolled / blunted polished edge slips across their surface.
