cpms30v on sharpmaker

E

E75

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Apr 18, 2013
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i have a spyderco paramilitary 2 in cpms30v and i also have a spyderco persistence in 8cr13mov. i can get a hair poping edge with the 8cr13mov but with the cpms30v i can not get it as sharp! so frustrating when i payed 5x more for for the para 2. u looked at the steel chart to see the what the difference in the carob content. the persistence carbon is .8 and the para is carbon 1.45 does this make it harder to put an edge on the blade?
the para does hold it edge long but still any tips? should i make more passes on my sharpmaker then what it tell you to do in the video it comes with?
 
The two are different steels, mfg. different. S30V is a powder metallurgy steel and contains vanadium a very hard element, especially after heat treating. Thus, keep sharpening on it. It does not require a diamond stone. You can do it on Norton SiC or India stones just work it more with light pressure. I don't know the make up of Sharp Maker stones. Good luck, DM
 
Are You using the sharpie trick to make sure you are hitting the cutting edge? Do you have a loupe to see what you are doing to the edge?
 
You just haven't hit the apex yet. It's going to take many more passes than 8cr13mov would. The good news is, Once you get it sharpened it will only need a couple passes to maintain as long as you don't damage the edge.

Use a magic marker to color the edge so you can see where you are at while you are sharpening.
 
BIG difference in abrasion-resistance between the two steels. S30V has much higher carbon and vanadium, forming abundant and very hard vanadium carbides in the steel. That means it doesn't abrade (grind/sharpen) as easily, and will take more time and/or harder abrasives. Diamond is best for S30V, as it'll abrade the carbides more efficiently. As mentioned, other abrasives like silicon carbide and aluminum oxide (Norton's India, as mentioned) will work too, but perhaps not as quickly for heavy grinding. S30V is also known for not holding a fine-shaving edge for very long (the vanadium carbides are somewhat larger than the grain of the remaining steel matrix, and that limits how fine the edge will get), but it still maintains a very tough working edge for longer cutting in very tough materials (cardboard, etc.). The very hard carbides are responsible for that, in this steel.

8Cr13MoV has less carbon and very little vanadium (almost none), meaning essentially no vanadium carbides. So, it sharpens up much more easily. It'll also take a very fine edge, assuming the heat treat is good. Not as durable for edge-holding as S30V, but still pretty good steel. Similar in chemistry/makeup to AUS-8 steel.


David
 
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I tried forever to get a really good edge on my S30V Para 2 with the Sharpmaker and finally got so frustrated that I broke down and bought a Wicked Edge. Now I can get hair whittling edges on the S30V. I never really took to the SM, so a friend is now using it.
 
The Sharpmaker is very good at touching up or maintaining most knives & steels, IF the existing bevels on the edge are already in good shape (symmetrical and not more obtuse than 40° inclusive; even better if less than that). If the edge angle is too wide or asymmetrical, then it becomes much more difficult to use effectively. Edge angles at 30° or less are a breeze to touch up on the SM. Almost every factory edge bevel I've seen could benefit from some further narrowing or refinement, and many aren't quite fully apexed either. Trying to 'fix' all those issues can sometimes be more trouble than it's worth, if attempting it on the SM alone.


David
 
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Exactly, Every factory edge I've ever seen had one or more issues. Different angle from one side to the other, inconsistent angle along the edges, waviness, over deburred or all of the above. Not something I'd want to correct on a SM.

Once I fix it on the edge pro or lansky maintaining is a breeze. Though I don't own a SM, I use a lansky turn box crock stick. Same concept just less options.
 
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