How to achieve less than 100 bess?

[3D Anvil]

I agree, edge retention is very important.

It's not often you see BESS results from 24 hours after initial sharpening. Rarely will your sub-100 BESS knife remain that way the next day, even without use.

Absolutely true!  Even the slightest amount of oxidation, even on very stainless steels, will raise BESS scores over 100.  That said, however, it's very easy to bring the scores back down with light stropping, or even cutting stuff that isn't super abrasive.  I think that's why Wootz found improvement in his BESS scores when testing cutting boards, after the first couple of cuts.

[DT]

So ... how sharp is sharp enough?

[3D Anvil]

So ... how sharp is sharp enough?

The answer is obviously ... depends.   

My opinion has changed over time.  Used to be, I wasn't happy unless I could get a knife to 75 BESS or lower.  Nowadays I'm satisfied if it's under 100 after sharpening.  I almost always do a 15 dps edge, and I can maintain edges in the 100-120 range with stropping for quite a long time before I need to resharpen.  If I can't get it back to 120ish, then it's time for a fresh edge.

But I think most of us have standards that are wildly different from the general public.                                                                                                                                                                                                                                                                                                 

[Ken S]

"Under 100 BESS" what does that mean? I think we must determine whether the significance is the number itself or what it signifies. One of my three BESS testers is an older model of the PB-50C. With its accuracy of 25g, it is the bottom of the BESS totem pole. Most of us would probably turn up our noses at it. However, if we are not concerned with an actual number, it can serve as a "go-no go" indicator of the existance of remaining burr. (Full disclosure; my older PB-50B is my go to tester and the tester Edge on Up recommends for most users.)

I believe Wootz of Knifegrinders had his priorities straight in his video where he discussed how many would be content with a BESS in the 130 range, whereas he knew that that test indicated residual burr which would shorten the duration of sharpness.

I do not doubt that many of you are aware of this. My point is, for the benefit of our users newer to BESS, I believe it is important to state the goal is complete burr removal.  The actual BESS number is a byproduct of this, not the objective itself.

Ken

[Sir Amwell]

Well put Ken. Couldn't agree more.

[Ken S]

Thanks, Sir A.

Ken

[tgbto]

And for those who can't/won't spend that much on BESS hardware, a simpler approach with a cheap microscope and nylon wire (fishing line) can be a good burr detector : mark a point along the edge with a sharpie, set the wire down on a board, align the wire and the sharpie mark, cut the wire using a downward-only (not rocking) movement, ideally not all the way through the wire, and check the spot under the microscope. A dent in the blade will be an excellent indicator of a burr remaining along the apex.

All for under 20 bucks. Easily made even better with a support that will hold the wire taunt an inch above the board while cutting.

[tgbto]

And for those who can't/won't spend that much on BESS hardware, a simpler approach with a cheap microscope and nylon wire (fishing line) can be a good burr detector : mark a point along the edge with a sharpie, set the wire down on a board, align the wire and the sharpie mark, cut the wire using a downward-only (not rocking) movement, ideally not all the way through the wire, and check the spot under the microscope. A dent in the blade will be an excellent indicator of a burr remaining along the apex.

All for under 20 bucks. Easily made even better with a support that will hold the wire taunt an inch above the board while cutting, done in like 5 minutes with a chisel and a 2x2x2 wood block.

[John_B]

And for those who can't/won't spend that much on BESS hardware, a simpler approach with a cheap microscope and nylon wire (fishing line) can be a good burr detector : mark a point along the edge with a sharpie, set the wire down on a board, align the wire and the sharpie mark, cut the wire using a downward-only (not rocking) movement, ideally not all the way through the wire, and check the spot under the microscope. A dent in the blade will be an excellent indicator of a burr remaining along the apex.

All for under 20 bucks. Easily made even better with a support that will hold the wire taunt an inch above the board while cutting.

Like the BESS tester this only gives you a sense of a burr for one spot. I find that slowly cutting a thermal receipt along the entire blade you can feel if there is a burr. I hold the handle with thumb and a finger for sensitivity. I have not had one customer that has not commented later on how sharp their knives were.

[DT]

I couldn't agree more.  I'm a big fan of cutting paper.  I restored a fixed blade hunting knife for a friend yesterday. The final BESS score was 135.  I try for 75-95.

As I hone a knife, I slice thermal paper to check sharpness before I ever check it with the BESS tester.  I just lay the knife in the palm of my hand. 

I thought the blade was slicing paper a little better than usual.  When I checked it, the BESS score was 135. I was disappointed that the score wasn't sub 100 but I left it at that.  I believe the thin paper over the BESS tester.  The tester is checking only one tiny place and it is so easy for me to mess up the test.

When slowly cutting thin paper with the blade lying on my palm, the blade will stop on every nick and will not slice paper to my satisfaction until it is crazy sharp.

[3D Anvil]

I can usually tell from slicing paper (I use the Uline catalogue) what the BESS score is going to be, give or take 10-15 grams.  Whittling hair is another good analogue for the BESS tester.  If you can't whittle a hair (or cause it to split on contact), you've probably got a BESS reading over 135.  If you can whittle a hair, but you have to mess around with it for a while to get it, you're likely in the 110-135 range.  If you can do it on the first attempt, and pretty much anywhere on the edge, you're below 100.

As far as the BESS tester only reading a tiny fraction of the edge goes, I don't find that to be a problem.  My edges are generally consistent from tip to heel after sharpening.  If I get a reading of 100g in one spot, I'm going to get the same reading +/- 5g anywhere else on the blade.