N690Co sharpening angle

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Feb 23, 2016
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This Christmas I was given a Bastinelli Kalinou and I love it. However, when i cut a zip tie the edge rolled along about 1/4” of the edge. I didn’t slide the blade under the zip tie and twist to cut it, i slid it under and pulled straight away. I sharpened one side of the edge to about 15 degrees but left the other side at whatever it was from the factory (I think it was about 20 per side, I only left it like that because I was lazy and knew I would have time to fix it once i got back to college). After drawing it a few times from the kydex sheath, and cutting paper and some light plastic wrapping, (a few times I messed up and snagged it on the sheath) I noticed a roll on the edge.

I would like to know whether this is typical of N690Co, and what angle it should be able to support. Also, does anybody know how Fox does the final sharpening before the knife leaves the factory? I am thinking that if they use a belt sander, the heat treatment of just the edge may have been ruined and that would explain the issues with the edge. As always any helpful input is greatly appreciated, thanks in advance.
 
Rolling is better than chipping. Can you run it along a steel (the rod that comes with most chefs knives kits). It will probably straighten it right up. Then see what you may need to resolve the edge if anything.

Being that it's not a very wear resistant steel it may be good to go with 20 vs 15. It should help with any further issues.
 
I'd be willing to bet, being this knife is karambit and made for 'protection', it's likely not hardened to very high RC; especially if it rolled in cutting a zip-tie. N690Co is similar to something like 440C or VG-10. At decent hardness, they should handle zip-ties pretty easily. Even 420HC or 440A should handle that well, at hardness in mid-high 50s HRC or higher.

Another possibility could just be some heat damage near the edge, from the factory finishing of the edge. It happens sometimes, and the edge gets overheated in grinding the edge or in burr-removal with powered buffing wheels, which damages and weakens the steel near the edge. Grinding away the 'stressed' steel near the edge, and then resetting the bevels can usually fix that.

Wear-resistance doesn't matter with edge-rolling, BTW. The issue is more about the blade's heat-treated hardness, which will (or won't) protect it from rolling or chipping. Wear-resistance matters in abrasive cutting, in reducing the tendency for the edge to be ground away in abrasive materials.
 
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Thanks guys, does anybody know about what hardness the kalinou should be at? I can’t find anything online.
 
Thanks guys, does anybody know about what hardness the kalinou should be at? I can’t find anything online.

I couldn't find it either. For a frame of reference, I mentioned other steels like 420HC, 440A being able to handle zip-ties. Knives I've used in these types of steels, which handle the task easily, are generally in the HRC ~56-58 range, give or take a point or so. Think of knives from makers like Case or Buck, in their 420HC stainless. I'd start to be concerned about zip-tie cutting, if the blade I'm using were somewhere around HRC 55 or lower. At that threshold, edges can be noticeably more soft in some relatively common cutting chores.

Another thing to look for: a heavy burr along the edge could roll pretty easily as well. Whether the result of factory finishing or sharpening afterward, it's something to consider.

You've also mentioned a Kydex sheath. I know some people have had issues with those before, in dulling edges as the knife is drawn from, or inserted into the sheath. In some cases, it seems Kydex manufacturing & finishing can be a pretty dirty process, with abrasive grit from sanding tools getting embedded in the material during finishing. That may also be something to watch for.
 
Sounds like it has poor edge stability. Likely it will go away with some sharpening sessions, though I can’t say for sure. I have heard of Zip ties damaging many edges that should have been able to up tonn
 
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