- Sep 2, 2007
I put a photo up on the Spyderco forums.
If you’re truly interested send Boye an email he does custom versions of his folders. He can also give you any info like how thick the blade behind the edge it.
Apparently he is quite proud of his hollow grind. He claims that most hollow grinds suddenly bulge out just before the very edge. You can feel it by pinching a hollow ground knife blade between your thumb and forefinger and then dragging your fingers down the blade and over the edge. (Dragging from the direction of the spine to the edge)
On almost every hollow ground knife you will feel the blade bulges out a little bit just before the edge slips out of your fingers. This is due to the fact that hollow grinds tend to be done with a circular wheel on each side of the blade. If we look at these two OO’s we could imagine they are the circular grinding wheels. Boye does his hollow grind so the edge would be right at the part where the two OO’s touch, exactly 3 o clock on the left O and 9 o clock on the right where the edge would be the thinnest.
Most knives that are hollow ground would have the edge just a tiny bit lower on those two OO’s. Past 3 and 9 oclock the space between the wheels starts to widen. That is why on most hollow ground knives you can feel the blade bulge abit thicker just as you drag your pinched fingers down from the spine and over the edge. Boye’s knives don’t have this bulge.
Also he claims his knive are very easy to sharpen because the cobalt matrix the carbides sit in sharpens easily and it is the carbides in that cut.
What I have done is rank the steels in Categories based on edge retention cutting 5/8" manila rope. We are looking for big differences here, not ranking the steels in order such as 1,2,3,4,5. The categories or groups mean that one can expect those steels in that category to have close to the same performance as the other steels in the same category. The categories are ranked in order by edge retention, category 1 will have better performance than category 2 etc.
The Custom Phil Wilson knives in M390 (62) and ELMAX (62) are not added to the data, they wouldn't fit into any of the Categories due to the Optimal HT and cutting ability, the difference is off the scale percentage wise so it wasn't added.
The Testing Process is as follows:
Cutting 5/8" Manila rope on a Scale with wood to cut on. The scale was calibrated for the weight of the wood. Making 3 to 4 slicing cuts from back to tip using the least amount of down force needed to get the starting down force. Once that was established 20 cuts were made then down force was tested again and that continued until 20 LBS was reached.
All the knives started at 14 ~ 15 LBS of down force except for M390 because it cuts so aggressively.
Accuracy is to + or - 10 Cuts and + or - 1 LB of down force or 6%. This was verified doing a blind test of blades of unknown hardness until they were tested after. 2 blades of the same hardness and steel, sharpened the same and same model of knife.
RC hardness is + or - 1 RC on the steels that were tested as the standard of RC testing.
All edges were at 30 degrees inclusive and polished to 6000 grit on the Edge Pro, sharpness was tested by slicing TP clean.
The following data is the results that I got based on the above method, while not conclusive or the end all beat all data it is very accurate.
More steels will be added as they are tested.
CPM-S90V (Military and Para 2) (60)
CTS-20CP (Para 2) (60)
M390 (Mule) (60.5)
CTS - 204P (Para 2)
CPM M4 (62.5)
CPM-S90V (59) (Manix 2 with 30 Degree Micro Bevel)
VANAX 75 (Kershaw Tilt)
Vanax 35 (59.5)
CTS-XHP (Military) (60+)
Super Blue (61.5)
CPM 3V (Big Chris)
CPM - D2 (62)
ELMAX (58.5) Mule
D2 - Dozier K2
440C (Big Chris)
420 HC (Buck 110)
Same method as above, but with a coarse edge, 400 grit congress Silicone carbide, more optimal edge finish for max edge retention to highlight the differences in the steels.
Steel - # of cuts - Model - HRC Hardness - Geometry Measurement -
CPM 10V - 2400 - Phil Wilson Coyote Meadow - 64.5 RC - .004" behind the edge
CPM S125V - 2340 - Phil Wilson Bow River - 62.5 RC - .006" behind the edge
CPM S125V - 1960 - Big Chris Custom - 63.5 RC - .006 behind the edge
MAXAMET - 1940 - Spyderco MT-24 - 67-68 RC - .018" Behind the edge
CPM 10V - 1180 - Darrin Sanders Custom - 63 RC - .012" behind the edge
S110V - 1120 - Manix 2 - 62 RC - Regrind to .005" behind the edge.
CPM 10V - 1100 - Spyderco/Farid K2 - 63 HRC - .020" behind the edge.
CPM S110V - 1080 - Spyderco Military - 63-64 RC - .020" Behind the edge
CPM 20CV - 960 - Michael Raymond Starlit - 62 RC - .007" - .008" behind the edge
Z-A11 - 880 - Darrion Sanders Custom - 62.5 RC - .020" behind the edge/.070" spine thickness.
REX-45 - 840 - Spyderco Military - (? HRC) - .023" behind the edge
K390 - 820 - Mule - 62-64 RC
CPM S35VN - 760 - Darrin Sanders Custom - 62 - 62.5 RC - .006" behind the edge
CPM 4V - 740 - Big Chris Custom - 63 RC - .008" - .010" Behind the edge.
CPM M4 - 740 - Phil Wilson Custom - 65 RC - .015" Behind the edge.
S110V - 720 - Manix 2 - 62 RC - .030" behind the edge
Cru-Wear - 700 - Phil Wilson Custom Bow River - 63 RC - .005" behind the edge.
S30V - 620 - Michael Raymond Estrella Custom - 60.5 - 61 RC - .006" behind the edge
S110V - 600 - Mule - 60 RC - .015" -.018" behind the edge.
S90V - 600 - Benchmade 940-1 - 59-61 RC - .018" Behind the edge.
S35VN - 560 - Fiddleback Forge Kephart - 60-61 RC - .015" Behind the Edge.
CTS-XHP - 540 - Cold Steel Ultimate Hunter - 63.5 RC - .020" behind the edge
CPM M4 - 500 - Spyderco Gayle Bradley - 62.5 - .022" behind the edge
S90V - 460 - Military - 60 RC
S90V/CPM 154 - Para 2 - 460 - ? RC
White Steel Laminate - 460 - HSC Custom - 63-64 HRC - .020" behind the edge
RWL-34 - Mule Team 22 - 440 - 61-62 RC - .020" Behind the edge
CTS 204P - 420 - Para 2
ZDP -189 - 420 - Endura 4 - 65 RC
Niolox - 420 - LX Blades - 59 - 59.5 RC - .006" behind the edge
BD1N - 420 - Phil Wilson - 60 HRC - .020" behind the edge
M390 - 400 - Benchmade 810-1401 Contego 60-62 RC
M390 - 380 - Military - 61 RC
ELMAX - 340 - ZT 0770CF - ? RC
ELMAX - 340 - Para 2 - ? RC
AEB-L - 340 - Tim Johnson Custom - 60 RC - .006" behind the edge
HAP-40 - 320 - Spyderco Endura - ? RC - .024" behind the edge
S35VN - 320 - Chris Reeve Sebenza 25 - ? RC - .021" behind the edge
CruForgeV - 300 - Bluntcut Custom - 62 HRC - .012" behind the edge
S30V - 300 - Military - 60 RC
PSF-27 - 280 - MT-19 - ? RC
Cru-Wear - 260 - Military - ? RC
CTS-XHP - 240 - Military - 60.5 RC
CTS-B75P - 240 - Mule
Sleipner - 240 - LionSteel PM2
Dozier D2 - 220 - Dozier K2
ELMAX - 220 - Mule - 58.5 RC
VG-10 - 160 - Stretch
AUS-8A - 160 - Recon 1
12c27 MOD - 120 - Opinel #8 - .012" behind the edge
XC90 - 80 - Opinel #8 - .012" behind the edge