Edge Retention: ZDP-189 and 8cr14mov

michaelm466

michaelm466

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Mar 5, 2009
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Not a super scientific or controlled test, but though I'd post up my experience with these two steels using them for about 4 hours non stop. I work at a clothing store where we have to cut up (make damaged/returned/washed and worn clothes unwearable and unreturnable if some one took them out of the dumpster) clothes. The clothes consisted of about 25% blue jeans, 10-15% shoes, mostly foam and rubber flip flops that have to have the sole cut in half, about a third other shoes that have vinyl, leather and harder rubber or plastic materials to cut through, and the rest lighter weight shirts, dresses, skirts etc. Most are a little dirty and are probably holding a little dirt that probably causes extra wear compared to just plain denim or t-shirt material. Denim Jeans received about 2 cuts per leg the length of the inseam and the 1x2 brand tag on the waist had to be cut out on each pair as well wear the denim is double thickness. All shoes were cut in half at mid sole, as well as the rubber or leather straps (two on flip flops, about six on the thicker leather womens shoes.) t-shirts, skirts and other lighter materials received about 5, 6-12 inch cuts per item.

I used a Spyderco Delica ZDP-189 (saber grind version) blade that had been reprofiled to about 25 degrees inclusive with a near mirror polish and a Benchmade vex with 8cr14mov steel that is at about 30 degrees inclusive with a near mirror polish as well. I made it through 95-105 items before the delica could no longer scrape shave or shave hair in anyway, and continued on to 160 items before moving on to the Vex. The Vex made it to 35 before the Vex could no longer shave. after about 70 items with the Vex I was finding it was taking a lot of force to go through. I then felt the edge with my thumb, the vex felt sharper, perhaps toothier, but the delica was definitely going through the clothing easier, with less force. Continued on with the delica for another 50 items before I finished with all the "damages", Both were quite dull when I got them home, but the delica at 200 went through clothes easier than the Vex would. Neither would push cut printer paper, the delica took about 20 minutes to sharpen back up to its original state, the Vex took about 5. Neither had chips or visible edge deformation.

This is all for what its worth, I picked up items as randomly as I could so hopefully both knives got about an even and equal mix of jeans, t-shirts and shoes. If I could have done this more scientifically I would have made sure I did exactly the same number of items and item types, length of cuts etc. And repeated that same process at least 10 times or so, but I was on the clock at work so hopefully this is at least somewhat usefull. I hope to try my S30V Paramilitary, M390 BM 710, and CTS-XHP Manix 2 next.
 
Very interesting. :D

Let us know how the other knives and steels do for sure. :)
 
Interesting read. Big difference between the two knives. I'm looking forward to your BM 710 M390 test, as I just ordered one and can't wait until it arrives.
 
michaelm this is just the kind of test usage we need--real life ,hard cutting to show the grit of a knife. thanks a ton for posting & we look forward to hearing more from yourself.
dennis
 
Now sharpen that Delica with the same edge angle up to 600 grit diamond and strop the burr away on leather loaded with green chromium compound.

A couple of years back we used the exact same Delica ZDP189 sabergrind with about the same edge angle on cutting corrugated cardboard at work all day long.
I sharpened the knife while my collegue did all the cutting.
The polished edge lasted only a couple of hours (then it began to tear), while the toothy edge lasted several days doing the same work without tearing.
We didn't check on shaving ability, just wanted to find out which type of edge lasted longer on just cutting cardboard.
 
kwackster said:
Now sharpen that Delica with the same edge angle up to 600 grit diamond and strop the burr away on leather loaded with green chromium compound.

A couple of years back we used the exact same Delica ZDP189 sabergrind with about the same edge angle on cutting corrugated cardboard at work all day long.
I sharpened the knife while my collegue did all the cutting.
The polished edge lasted only a couple of hours (then it began to tear), while the toothy edge lasted several days doing the same work without tearing.
We didn't check on shaving ability, just wanted to find out which type of edge lasted longer on just cutting cardboard.
Click to expand...

Very interesting results, I'll definitely have to try that with my delica as well, and see if I get the same results with the clothes.
 
Thanks for the post. You should not do any excuse - this is not scientific lab test, but it is perfectly scientific, because you provide all details to understand your procedure.

There are not too many people who have exposure to such an extensive blade use, I had to buy manila rope for my testing, while you have payed for doing this! If you just record your experience and findings as you just did - it will be quite valuable input and perfectly scientific for me (while it is not a sterile lab, but still important data).

Please, try coarse edge and let us know.

Thanks, Vassili.
 
I am very interested to see your reports on the Para, 710, and Manix 2. This is real world performance testing.
 
I 'm very interesting too about your report on the S30V and the others possible steels.
It is kind of real life test.
 
A 1x30 Belt Sander from Harbor freight. To reprofile I start at 600 grit, then 800, then 1000 (highest I could find) and last a leather belt with compound on it to, sometimes after that a couple passes on a hand strop with finer compound. If its already been reprofiled I usually just use the leather 1x30 with compound unless its really dull then I start at the 1000 then the leather.
 
Yep, interesting read. Thanks for putting this up. I'd be interested in how other steels do with your usage.
 
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