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JBroida
04-26-2011, 03:55 AM
I just wrote up a long response to someone on another forum and thought it might be useful for many other people as well... i was discussing new single bevel knives, high and low spots, and flattening the bevel, and different grinds. Enjoy...

Often times, new knives ship with high or low spots. These are more prevalent in less expensive knives for the most part (though not absent from higher prices ones). Also, they tend to be near the tip and heel more often than in other areas.

Flattening the bevel is an interesting thing. First of all, not everyone agrees that you should do this. Many knife makers will recommend that you just continue to sharpen normally (which in their mind is the hamaguriba edge i often describe) and the spots will do away over time. Hamaguriba edges involve 2 distinct bevels that are blended together, so chances are you will be sharpening the edge even if you have a high or low spot. Over time, the spots will disappear. In the meantime you can do certain things to cover up the spots... i.e. use a really muddy stone around 3-6k with super light pressure... this fills in high and low spots for a nice look even though they will still be there.

Another type of sharpening, and one that is commonly practiced by busier chefs, is to grind a single bevel into the edge. This will take a lot more work initially as you will actually have to grind out the high and low spots before you start to see a good edge. However, if you cant get it all done at once, you can put a tiny (and i mean TINY) microbevel on the knife to give it a working edge until you sharpen it again, thus removing the high and low spots and also the microbevel.

Flat ground edges (or flat ground with the slightest of convexivity from hand wobble or differential pressure) will feel slightly sharper, but will be a little more brittle. These can work if you arent doing high volume or if you sharpen often.

Hamagruiba edges will be more durable and work well when you have higher volume or arent sharpening every day. You loose the slightest bit of sharpness in favor of a durable edge for kitchen use.

You can also mix things up with microbevels, which work on both hamaguriba and flat ground edges. You will find that microbevels work better for some steels and heat treatments than others and better for some tasks than others.

-Jon

l r harner
04-26-2011, 09:01 AM
good read thats why i was so messed up. i thought i could save the buyer a step by flat grinding or hollow grinding super thin (i check koften to see where the high and low spots are and fix the while grinding )

Dave Martell
04-26-2011, 11:40 AM
Good post Jon, spot on.

Jim
04-26-2011, 12:17 PM
Thanks Jon!

Eamon Burke
04-26-2011, 11:21 PM
This is a good summary!

That said, for anyone who stumbles here searching for knowledge, my opinion is that there's no practical advantage to futzing around getting perfectly dead-flat bevels in a kitchen.

JBroida
04-26-2011, 11:29 PM
This is a good summary!

That said, for anyone who stumbles here searching for knowledge, my opinion is that there's no practical advantage to futzing around getting perfectly dead-flat bevels in a kitchen.

except in some cases the ease of sharpening versus hamaguriba... but only if you are well versed with sharpening and using these knives so that you know exactly what you will be getting (i.e. the tradeoffs)

Eamon Burke
04-27-2011, 10:37 PM
Ah I see what you are saying. Makes sense.