Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
Small Sebenza, Pacific Salt and Bryd Meadowlark, all blades were reprofiled flat to the primary grinds, this left primary grind edges of 5.8, 6.5, and 6.3 degrees respectively. The blades were then hand sharpened on waterstones to a fine polish (mainly to check ease of resharpening) and then a 20 degree micro-bevel applied to a fine polish with a Sharpmaker using a Jeff Clarks's burr removal method.
I wanted this to be a rougher sort of test meaning not making an attempt to be overly quantitative could a difference be readily seen in the blades. Considering the massive difference in the steels and the price this would seem to be likely. The main criteria to judge performance was the ability to cut paper. There were three main benchmarks :
1) push cut at 90
2) push cut at 45
3) slice at 45
There were three runs of cutting performed on the plywood, which was 3/8" thick, 2" long cuts made 1/16"-1/32" deep. A total of 310 cuts were made and the sharpness was checked every 10*2^n cuts. Before each round the micro-bevel was completely cut off, any damage was removed with a x-coarse waterstone and the bevel reset.
All blades started off easily doing a push cut at 90, in general the Sebenza was sharper than the Pacific Salt which was sharper than the Meadowlark in terms of smoothness of cut. The differences were small but they could easily be felt. It could be noticed when shaving as well.
During the first round heavy force was applied (75 lbs) so the cuts were fast, the Sebenza chipped out heavily during the first ten slices and lost a piece of the edge a millimeter deep. I continued with it up to 150 cuts and by that time it had several visible pieces out of the edge and the entire edge was distorted.
The Pacific Salt and Meadowlark lost the 90 degree push cutting ability after 10 cuts, but kept the ability to push cut at 45 until 150 cuts and after 310 slices could still do the 45 degree slice easily. The Meadowlark was ahead of the Pacific Salt but they were very close, I checked it on light cotton and the Pacific Salt was 21 (11) % more degraded, just barely on the point of significance (the cotton was the average of all three rounds).
For the next round the force was backed way off, less than half of full, the Sebenza still took severe damage after the first ten cuts and the edge was visbly distorted. Checked under magnification the microbevel had cracked off from 1/2 to 3/4 width (0.15 mm wide), in the contact region. No more cutting was attempted with it. The other two knives went right to 310 cuts with the same behavior as before.
For the final round very light force was used (15 lbs), the Sebenza now did the first ten cuts with no damage, however after the next 20 cuts it was chipped out to less than half its micro-bevel. In the places not chipped it was still able to push cut at 90 so was sharper than the other blades. After another 40 cuts the Sebenza just lost the push cutting ability at 90 but in some sections the micro-bevel was again just cracked off in places. Cutting was suspended with it again.
The performance of the Meadowlark and Pacific Salt was consistent in the final run. What was interesting is that it made no difference to those blades if the force was 75 lbs or 15 lbs, they looked exactly the same at the end. After 310 cuts most of the micro-bevel would be removed on both blades, however in this state, due to the thin nature of the primary edge, they could still readily slice newsprint, so most would consider them still sharp.
As a final check, I micro-beveled the Pacific Salt and Meadowlark with micro-bevels taking twice as many passes on the fine rods (20 per side) to thicken the bevels to see if that made any difference, I didn't see how it would, but it never hurts to check. It made no difference at all. They blunted exactly the same. The complete sharpening process was :
-reset edge on x-coarse SiC waterstone
-polish on 800,1000, 4000, natural chinese waterstone
-10 passes per side at 20 degrees on medium Sharpmaker
-deburr at 30 degrees per side, 2 passes on fine ceramics
-hone edge at ten passes per side on fine ceramics at 20
Note while the primary edge bevels were very acute (around six degrees) due to hand sharpening there was a convexity to the bevels so they increased in angle towards the very edge. The actual edge bevel in the last 1/8" was 10.0 (5), 10.5 (4), and 10.3 (5) for the small Sebenza, Meadowlark and Pacific Salt respectively.
The performance is interesting for several reasons, first that H1 can match 8Cr13MoV which means I need another reference point, is H1 high or the other low. I need to run VG-10 on the plywood and see what happen to it, and then maybe M2, D2 and other tool steels.
Secondly what happened to S30V, the performance was so lopsided it wasn't even in the same class, the damage with the other two blades was much less extensive even after much more cutting with much more force, many to one in both aspects. I need to check this with other S30V blades.
No plywood on hand currently though.
-Cliff
I wanted this to be a rougher sort of test meaning not making an attempt to be overly quantitative could a difference be readily seen in the blades. Considering the massive difference in the steels and the price this would seem to be likely. The main criteria to judge performance was the ability to cut paper. There were three main benchmarks :
1) push cut at 90
2) push cut at 45
3) slice at 45
There were three runs of cutting performed on the plywood, which was 3/8" thick, 2" long cuts made 1/16"-1/32" deep. A total of 310 cuts were made and the sharpness was checked every 10*2^n cuts. Before each round the micro-bevel was completely cut off, any damage was removed with a x-coarse waterstone and the bevel reset.
All blades started off easily doing a push cut at 90, in general the Sebenza was sharper than the Pacific Salt which was sharper than the Meadowlark in terms of smoothness of cut. The differences were small but they could easily be felt. It could be noticed when shaving as well.
During the first round heavy force was applied (75 lbs) so the cuts were fast, the Sebenza chipped out heavily during the first ten slices and lost a piece of the edge a millimeter deep. I continued with it up to 150 cuts and by that time it had several visible pieces out of the edge and the entire edge was distorted.
The Pacific Salt and Meadowlark lost the 90 degree push cutting ability after 10 cuts, but kept the ability to push cut at 45 until 150 cuts and after 310 slices could still do the 45 degree slice easily. The Meadowlark was ahead of the Pacific Salt but they were very close, I checked it on light cotton and the Pacific Salt was 21 (11) % more degraded, just barely on the point of significance (the cotton was the average of all three rounds).
For the next round the force was backed way off, less than half of full, the Sebenza still took severe damage after the first ten cuts and the edge was visbly distorted. Checked under magnification the microbevel had cracked off from 1/2 to 3/4 width (0.15 mm wide), in the contact region. No more cutting was attempted with it. The other two knives went right to 310 cuts with the same behavior as before.
For the final round very light force was used (15 lbs), the Sebenza now did the first ten cuts with no damage, however after the next 20 cuts it was chipped out to less than half its micro-bevel. In the places not chipped it was still able to push cut at 90 so was sharper than the other blades. After another 40 cuts the Sebenza just lost the push cutting ability at 90 but in some sections the micro-bevel was again just cracked off in places. Cutting was suspended with it again.
The performance of the Meadowlark and Pacific Salt was consistent in the final run. What was interesting is that it made no difference to those blades if the force was 75 lbs or 15 lbs, they looked exactly the same at the end. After 310 cuts most of the micro-bevel would be removed on both blades, however in this state, due to the thin nature of the primary edge, they could still readily slice newsprint, so most would consider them still sharp.
As a final check, I micro-beveled the Pacific Salt and Meadowlark with micro-bevels taking twice as many passes on the fine rods (20 per side) to thicken the bevels to see if that made any difference, I didn't see how it would, but it never hurts to check. It made no difference at all. They blunted exactly the same. The complete sharpening process was :
-reset edge on x-coarse SiC waterstone
-polish on 800,1000, 4000, natural chinese waterstone
-10 passes per side at 20 degrees on medium Sharpmaker
-deburr at 30 degrees per side, 2 passes on fine ceramics
-hone edge at ten passes per side on fine ceramics at 20
Note while the primary edge bevels were very acute (around six degrees) due to hand sharpening there was a convexity to the bevels so they increased in angle towards the very edge. The actual edge bevel in the last 1/8" was 10.0 (5), 10.5 (4), and 10.3 (5) for the small Sebenza, Meadowlark and Pacific Salt respectively.
The performance is interesting for several reasons, first that H1 can match 8Cr13MoV which means I need another reference point, is H1 high or the other low. I need to run VG-10 on the plywood and see what happen to it, and then maybe M2, D2 and other tool steels.
Secondly what happened to S30V, the performance was so lopsided it wasn't even in the same class, the damage with the other two blades was much less extensive even after much more cutting with much more force, many to one in both aspects. I need to check this with other S30V blades.
No plywood on hand currently though.
-Cliff
please send it to me and i'll give you a Spyderco in S30V !
