Victorinox Fibrox: edge analysis of 5.2063.20 and 5.2003.15

[mengwong]

In 24 hours I will be able to report actual measurements, please hold.

So … I summoned an 8" chef's knife and a 6" chef's knife.

Generally speaking, at mid-knife and tip, there appears to be a low-angle 10–12° back bevel convexing to a 15° to 20° microbevel. The heel shows around 10–12° on the left, about 9–22° on the right. So there is a tiny bit of right-hand-bias, if you want to call it that.

Here are the measurements:

5.2003.15 6" Chef's Knife (47570)​

Goniometry​

tip: 10° back bevel, concaving to 20° microbevel at edge
mid: left 10–15°; right 10–19°
heel: left 12°; right 12–22°

I think I'm reading it right. Source images below.

BESS​

tip: 128
mid: 123
heel: 144

microscopy​

Can't complain.

5.2063.20 8" Chef's Knife (40520, 47520, & 45520)​

Goniometry​

tip: 11° back bevel, convexing to 22° microbevel at edge
mid: left 10–15°; right 9–19°
heel: left 10–13°; right 9–22°

BESS
tip: 125
mid: 110
heel: 104

microscopy​

We tilt the edge to see some reflections so you can gauge the beveling.


There was perhaps a very small foil burr: viewed from one angle, very little reflection

but tilted just a little more, a bright line appears.

Still, very good.

The OOTB sharpness of the 8" Victorinox Fibrox Pro is comparable to my hand-sharpened Sakai Kikumori nihonkou gyuto (after a couple weeks of light use) which also returns results around 100–130 BESS.

Methodology​

For microscope scale, please see Freehand Sharpening with Microscope Pics

from start to finish … don't mind the heavy breathing, sorry about that.

Goniometry Details: 8" 5.2063.20​

Goniometry Details: 6" 5.2003.15

 

[r0bz]

what is that ?
can you explain

 

[blokey]

Blade angle, seems they are still 20 per side, which is good.

 

[mengwong]

Summary: at mid-knife and tip, there appears to be a low-angle 10–12° back bevel convexing to a 15° to 20° microbevel. The heel shows around 10–12° on the left, about 9–22° on the right. So there is a tiny bit of right-hand-bias, if you want to call it that.

I suspect the microbevel is throwing off the readings. Future work: I propose to Sharpie the apex and the, uh, hira, to see what the "kireha" back bevel angle is.

I performed "axial goniometry" with the apex and the hira partly masked by whiteboard marker.

A distinct bright spot was visible through most of the scan. The below photo, positioned at the arrow above, shows the bright spot at 10° on the Dexter/Recto/Stage-Right (D) side of the blade, while the Sinister/Verso/Stage-Left (S) side shows a continuous bright line up to about 10°. The edge faces us, so the "stage right" of the blade appears on the left of the image.

The tip appears to be ground closer to 20°, the mid-blade back/relief bevel at 10°–15° (indexing by the bright spot in the video). I'm guessing the photo above has a different gamma curve than the video for the bright red laser, due to HDR postprocessing, so the video is worth a look. Skip past the markering foreplay to see the axial scan near the end.

Based on the previous measurements without masked apex, the edge-bevel/micro-bevel then convexes back to 20–25° (D), 15–20° (S).



We regret the handheldedness of everything. I lack a device to hold things steady.

According to knives&tools they use 18°: Victorinox Fibrox chef's knife 20 cm 5.2063.20

The marker may not be enough to mask the unwanted parts of the knife. May try again with sharpie instead of whiteboard. Or with actual masking tape.

 

[stringer]

I performed "axial goniometry" with the apex and the hira partly masked by whiteboard marker.

View attachment 206959

A distinct bright spot was visible through most of the scan. The below photo, positioned at the arrow above, shows the bright spot at 10° on the Dexter/Recto/Stage-Right (D) side of the blade, while the Sinister/Verso/Stage-Left (S) side shows a continuous bright line up to about 10°. The edge faces us, so the "stage right" of the blade appears on the left of the image.

View attachment 206960

The tip appears to be ground closer to 20°, the mid-blade back/relief bevel at 10°–15° (indexing by the bright spot in the video). I'm guessing the photo above has a different gamma curve than the video for the bright red laser, due to HDR postprocessing, so the video is worth a look. Skip past the markering foreplay to see the axial scan near the end.

Based on the previous measurements without masked apex, the edge-bevel/micro-bevel then convexes back to 20–25° (D), 15–20° (S).



We regret the handheldedness of everything. I lack a device to hold things steady.



The marker may not be enough to mask the unwanted parts of the knife. May try again with sharpie instead of whiteboard. Or with actual masking tape.

That's really neat. Thanks for sharing

 

[Pie]

I like this approach, although my understanding of it is shaky. Well done.