What the heck is "ion fused surface of about 150 RC" Mean?

[d2eux]

Hi all. I'm looking at a discontinued sharpener/Hone put out by Kershaw called the "Edge Tek." Here is a description

Steel shaft with ion fused surface of about 150 RC

http://www.outdoorknifeexpress.com/sale/1611171/

 

[Obsessed with Edges]

It sounds similar to a V-crock sharpener I bought 20+ years ago. Don't remember the brand at the moment (mine wasn't Kershaw). It might've been a Smith's product, if my memory serves. Instead of a solid ceramic rod, as is used with most such sharpeners, mine had what appeared to be a ceramic coating over steel rods. I verified it was steel with a magnet, BTW. I didn't initially know it was just coated steel, until the abrasive surface started chipping off, even being scraped off by the blade's edge, exposing shiny metal underneath. At that point, the tool becomes useless.

So, if the model you're looking at is discontinued, there may be good reason for that. I personally see no reason why a manufacturer would go to such lengths as coating a steel rod with ceramic, when the 'pure' and solid ceramics aren't very expensive anyway. Only reason might be to toughen the rods, as a solid ceramic is very brittle, and can break easily if dropped. But if the 'ceramic' coating is still just as brittle, then there's the risk of the chipping problems I saw with mine, even the rod itself doesn't break.

If you don't have to pay much for it, there's no harm in giving it a try; maybe more recent manufacturing has fixed such problems as chipping, sloughing off, etc. But in that type of sharpener, I'd more likely be looking at a diamond/nickel coated rod instead (EZE-Lap has one that looks similar, in diamond/nickel), or just some other similar field sharpener with more commonly seen solid ceramic. I also see now, Kershaw is currently marketing a so-called 'Ultra-Tek' sharpener along the same lines (diamond over a plated, oval rod).

The '150 RC' description is essentially meaningless, other than to imply the surface is very hard. Assuming it's an aluminum oxide ceramic, that's a given anyway, being about 3X as hard as cutlery steel often measured in 50s-60s range on the Rockwell 'C' ('RC') scale. The Rockwell C hardness scale tops out in the low-80s at best (many HRC scales won't include anything over high-60s anyway), as there's no reliable way for that type of tester to quantify (accurately) anything harder. There are other, more accurate hardness testing means available for ceramics and other super-hard materials, such as the Knoop hardness test.


David

 

[cbwx34]

Hi all. I'm looking at a discontinued sharpener/Hone put out by Kershaw called the "Edge Tek."

Unless you have a particular need for this... i would look elsewhere. For $30... better options avail. (WorkSharp's Field Sharpener for example, can be found for around the same $, and would give you more options for sharpening & touching up a blade).

 

[danbot]

Sounds more like a measurement of surface roughness. Unless like the previous poster suggested its a theoretical Rockwell C hardness equivalent? RC is the mean height of surface profile elements. But it is hardly ever used. Usually surface roughness if reported in RA or RZ values. So, I would agree, its pretty much meaningless to the average person forsure. They were probably just trying so sound all scientific-y / tech-y for marketing purposes??

 

[jc57]

Looks like a honing steel with some sort of abrasive surface. They still make a similar product, https://kershaw.kaiusaltd.com/gear/gear/ultra-tek-blade-sharpener, which is basically a 600-grit diamond honing rod.

 

[d2eux]

Unless you have a particular need for this... i would look elsewhere. For $30... better options avail. (WorkSharp's Field Sharpener for example, can be found for around the same $, and would give you more options for sharpening & touching up a blade).

Thanks for the recommendation. I thought this was similar to the Kershaw "ultra tek" diamond sharpener 600 grit but it's a good thing I posted this before buying.

I was using a Schrade diamond rod sharpener the other day but it was pretty shoddy quality and I started seeking out better options. Plus it had that Prop 65 warning that goes "This product contains chemicals that is known to the state of california to cause cancer" so I didn't see much value in continuing to use it.

 

[d2eux]

It sounds similar to a V-crock sharpener I bought 20+ years ago. Don't remember the brand at the moment (mine wasn't Kershaw). It might've been a Smith's product, if my memory serves. Instead of a solid ceramic rod, as is used with most such sharpeners, mine had what appeared to be a ceramic coating over steel rods. I verified it was steel with a magnet, BTW. I didn't initially know it was just coated steel, until the abrasive surface started chipping off, even being scraped off by the blade's edge, exposing shiny metal underneath. At that point, the tool becomes useless.

So, if the model you're looking at is discontinued, there may be good reason for that. I personally see no reason why a manufacturer would go to such lengths as coating a steel rod with ceramic, when the 'pure' and solid ceramics aren't very expensive anyway. Only reason might be to toughen the rods, as a solid ceramic is very brittle, and can break easily if dropped. But if the 'ceramic' coating is still just as brittle, then there's the risk of the chipping problems I saw with mine, even the rod itself doesn't break.

If you don't have to pay much for it, there's no harm in giving it a try; maybe more recent manufacturing has fixed such problems as chipping, sloughing off, etc. But in that type of sharpener, I'd more likely be looking at a diamond/nickel coated rod instead (EZE-Lap has one that looks similar, in diamond/nickel), or just some other similar field sharpener with more commonly seen solid ceramic. I also see now, Kershaw is currently marketing a so-called 'Ultra-Tek' sharpener along the same lines (diamond over a plated, oval rod).

The '150 RC' description is essentially meaningless, other than to imply the surface is very hard. Assuming it's an aluminum oxide ceramic, that's a given anyway, being about 3X as hard as cutlery steel often measured in 50s-60s range on the Rockwell 'C' ('RC') scale. The Rockwell C hardness scale tops out in the low-80s at best (many HRC scales won't include anything over high-60s anyway), as there's no reliable way for that type of tester to quantify (accurately) anything harder. There are other, more accurate hardness testing means available for ceramics and other super-hard materials, such as the Knoop hardness test.


David

Thanks for clarifying. From what you said, it doesn't look like it's worth spending $25+ on to try. I guess I was fooled by the "made in USA" label. Kershaw used to have the Ultra Tek 600 grit Diamond Sharpener "made in USA" so I was seeking out other Kershaw sharpeners that might have still had the "made in USA" label.

 

[Obsessed with Edges]

Thanks for clarifying. From what you said, it doesn't look like it's worth spending $25+ on to try. I guess I was fooled by the "made in USA" label. Kershaw used to have the Ultra Tek 600 grit Diamond Sharpener "made in USA" so I was seeking out other Kershaw sharpeners that might have still had the "made in USA" label.

It may still be a decent tool, and I'm not deliberately trying to knock it. But, it seems sort of a gimmicky way to accomplish what other similar tools in nickel & diamond and/or solid ceramics can do, sometimes even for less money. If you ever have a chance to get one at a steal of a price on the 'Bay or wherever, it may be worth trying out. Otherwise, the ceramic-coated (or 'fused surface') steel rod concept seems unnecessary to me, and maybe prone to problems eventually. In looking at other listings of this tool on the web, it looks like they first came out back in the '90s sometime. I think that's about the same time frame I bought the coated steel rod tool I mentioned. Maybe the ceramic-coating technology was trendy then, but perhaps not yet tested well enough by time and use.

I THINK, unless things have changed recently, that many/most of EZE-Lap's similar sharpeners are still made in U.S.A. I've recently purchased (in the last 2-3 years) two diamond sharpeners from them that are domesticly manufactured. One is a 10" oval diamond 'chef's steel' for kitchen use, and the other is a dual-sided hone similar to DMT's Dia-Fold series (DMT is also U.S.A.-made, BTW). They're also of pretty decent quality at least, or even very good. Neither was very expensive either, at least as compared to this particular tool. Both were under $25-$30 apiece.


David

 

[Alberta Ed]

Sounds like a smooth steel, useful for realigning edges on softer steels such as used in professional cutlery... chefs often prefer knives with steels in the R55 range that can be easily resharpened. An old engine valve stem works perfectly -- ask around at a local machine shop that rebuilds engines. They probably have a bucket of old valves they'd be glad to get rid of.

 

[d2eux]

It may still be a decent tool, and I'm not deliberately trying to knock it. But, it seems sort of a gimmicky way to accomplish what other similar tools in nickel & diamond and/or solid ceramics can do, sometimes even for less money. If you ever have a chance to get one at a steal of a price on the 'Bay or wherever, it may be worth trying out. Otherwise, the ceramic-coated (or 'fused surface') steel rod concept seems unnecessary to me, and maybe prone to problems eventually. In looking at other listings of this tool on the web, it looks like they first came out back in the '90s sometime. I think that's about the same time frame I bought the coated steel rod tool I mentioned. Maybe the ceramic-coating technology was trendy then, but perhaps not yet tested well enough by time and use.

I THINK, unless things have changed recently, that many/most of EZE-Lap's similar sharpeners are still made in U.S.A. I've recently purchased (in the last 2-3 years) two diamond sharpeners from them that are domesticly manufactured. One is a 10" oval diamond 'chef's steel' for kitchen use, and the other is a dual-sided hone similar to DMT's Dia-Fold series (DMT is also U.S.A.-made, BTW). They're also of pretty decent quality at least, or even very good. Neither was very expensive either, at least as compared to this particular tool. Both were under $25-$30 apiece.


David

What you say makes sense, because this seller is selling one "as new", but it looks like the coating is wearing off and is even rust spots underneath?
http://www.ebay.com/itm/KERSHAW-252...LACK-NYLON-FOLDING-KNIFE-SHEATH-/362045129690

Good news though I found this Lanksy diamond sharpener made in USA

 

[Obsessed with Edges]

What you say makes sense, because this seller is selling one "as new", but it looks like the coating is wearing off and is even rust spots underneath?
http://www.ebay.com/itm/KERSHAW-252...LACK-NYLON-FOLDING-KNIFE-SHEATH-/362045129690

Good news though I found this Lanksy diamond sharpener made in USA

I couldn't say if the pictured item's coating is actually wearing off, or the substrate rusting. A 'new, old stock' 20-year-old sharpener could conceivably show some rust, if the storage conditions weren't controlled very well, and too humid at times. The 'rust' might also be some accumulated rusty swarf, if the 'AS NEW' description isn't totally honest and it's actually had some use (not accusing in this case, but speculating on what could leave some rust there, hypothetically). The rough appearance of the coating might be normal, as opposed to indicating wear. Most of these types of tools, if they're designed to remove much metal at all, will have a relatively rough surface, especially when they're new.


David

 

[annr]

It sounds similar to a V-crock sharpener I bought 20+ years ago. Don't remember the brand at the moment (mine wasn't Kershaw). It might've been a Smith's product, if my memory serves. Instead of a solid ceramic rod, as is used with most such sharpeners, mine had what appeared to be a ceramic coating over steel rods. I verified it was steel with a magnet, BTW. I didn't initially know it was just coated steel, until the abrasive surface started chipping off, even being scraped off by the blade's edge, exposing shiny metal underneath. At that point, the tool becomes useless.

So, if the model you're looking at is discontinued, there may be good reason for that. I personally see no reason why a manufacturer would go to such lengths as coating a steel rod with ceramic, when the 'pure' and solid ceramics aren't very expensive anyway. Only reason might be to toughen the rods, as a solid ceramic is very brittle, and can break easily if dropped. But if the 'ceramic' coating is still just as brittle, then there's the risk of the chipping problems I saw with mine, even the rod itself doesn't break.

If you don't have to pay much for it, there's no harm in giving it a try; maybe more recent manufacturing has fixed such problems as chipping, sloughing off, etc. But in that type of sharpener, I'd more likely be looking at a diamond/nickel coated rod instead (EZE-Lap has one that looks similar, in diamond/nickel), or just some other similar field sharpener with more commonly seen solid ceramic. I also see now, Kershaw is currently marketing a so-called 'Ultra-Tek' sharpener along the same lines (diamond over a plated, oval rod).

The '150 RC' description is essentially meaningless, other than to imply the surface is very hard. Assuming it's an aluminum oxide ceramic, that's a given anyway, being about 3X as hard as cutlery steel often measured in 50s-60s range on the Rockwell 'C' ('RC') scale. The Rockwell C hardness scale tops out in the low-80s at best (many HRC scales won't include anything over high-60s anyway), as there's no reliable way for that type of tester to quantify (accurately) anything harder. There are other, more accurate hardness testing means available for ceramics and other super-hard materials, such as the Knoop hardness test.


David

Do all of these come in nickel? Nickel is one of the commonest allergens.

The prevalence of metal allergy is high in the general population, and it is estimated that up to 17% of women and 3% of men are allergic to nickel and that 1-3% are allergic to cobalt and chromium.
https://www.ncbi.nlm.nih.gov/pubmed/19831422​

I checked the web and see mention of nickel backings, etc., on DMT stones. I didn't see anything specific about this on the DMT site nor any specifics by product. Would you know where to look or get more information?

Amazon lists "diamond, nickel and steel" for the Continuous Diamond and "Diamond-Coated Stainless Steel" (no nickel, or unknown nickel content for steel) for the DMT whetstone. This would matter to me as I often recommend these stones and had not thought about the nickel allergy before.

ETA: possibly another reason for the OP to pass on these items?

 

[Obsessed with Edges]

Do all of these come in nickel? Nickel is one of the commonest allergens.

The prevalence of metal allergy is high in the general population, and it is estimated that up to 17% of women and 3% of men are allergic to nickel and that 1-3% are allergic to cobalt and chromium.
https://www.ncbi.nlm.nih.gov/pubmed/19831422​

I checked the web and see mention of nickel backings, etc., on DMT stones. I didn't see anything specific about this on the DMT site nor any specifics by product. Would you know where to look or get more information?

Amazon lists "diamond, nickel and steel" for the Continuous Diamond and "Diamond-Coated Stainless Steel" (no nickel, or unknown nickel content for steel) for the DMT whetstone. This would matter to me as I often recommend these stones and had not thought about the nickel allergy before.

ETA: possibly another reason for the OP to pass on these items?

I've read that nickel can be an allergen for some people. But I've yet to hear about it being an issue with nickel-plated diamond hones, at all. I think the most common application of nickel, where it presents a larger allergy issue, is in jewelry, piercings or other types of implants (including surgical implants like joint replacements), etc, which are in direct and constant contact with a person's skin or body chemistry.

I've never worried about it, and I don't think I've heard of anyone having an issue with it in the relatively incidental and infrequent use of a diamond hone.


David

 

[annr]

I've read that nickel can be an allergen for some people. But I've yet to hear about it being an issue with nickel-plated diamond hones, at all. I think the most common application of nickel, where it presents a larger allergy issue, is in jewelry, piercings or other types of implants, etc, which are in direct and constant contact with a person's skin or body chemistry.

I've never worried about it, and I don't think I've heard of anyone having an issue with it in the relatively incidental and infrequent use of a diamond hone.


David

I suppose it depends on the individual and other variables. For some, foods high in nickel content are problematic. And if one were allergic, I don't know how incidental or inconsequential the use of one of these products would be.

Certainly I've abraded my fingertips and thumbs without incidence, for decades(!), which is tissue penetrating. I've never seen studies on this in the literature—haven't really looked either and doubt they have tested sharpening equipment!

Maybe next time I talk to a guy who's an expert in allergic contact dermatitis, I'll run this by him. I do know from speaking to him, the longer the exposure the greater the chance of developing an allergy.

From now on, I'm going to mention this to people and let them decide what is best. Thanks for bringing it to my attention!

 

[bucketstove]

Sounds more like a measurement of surface roughness. Unless like the previous poster suggested its a theoretical Rockwell C hardness equivalent? RC is the mean height of surface profile elements. But it is hardly ever used. Usually surface roughness if reported in RA or RZ values. So, I would agree, its pretty much meaningless to the average person forsure. They were probably just trying so sound all scientific-y / tech-y for marketing purposes??

Hi,
Sounds like Nitriding#Plasma_nitriding , a surface layer which could have knoop microhardness of 27000 HK which while off the HRC scale might be approximated at ~150HRC ( http://www.tribology-abc.com/calculators/hardness.htm says 163 HRC)
....
but yeah this gizmo is too expensive for what it is, a smooth chef steel