And that was before she learned how much space it would take up in the garage. I dont think it was stated when he was making push cuts and when he was making slicing cuts for example. AMS-S-7420 forged 52100 steel refined extra small grain structure.Test out well above 40 cuts in heavy Manila rope. Each knife was tested three times on the CATRA edge retention tester and the results averaged. Thanks Scott. All of them have excellent edge stability, which is something I value very highly. Do you think a less aggressive test media might be better for generating a “sharpness curve”? I assume differences between steels would be more apparent if sharpening out a chip, re-profiling to a different edge angle, or polishing to high finishes. For this study I use a guided system to maintain precise edge angles. The sand abrasive in the paper is useful in that it speeds up tests by dulling edges faster, using a natural abrasive that is found in some materials people cut with some regularity (such as rope or animal hide). There were also big CATRA datasets I wrote about in the previously linked articles. In this case the non-cryo knife had somewhat superior edge retention because it was somewhat harder. Technically any media of an appropriate size could be put in rather than the standard silica-impregnated paper but thus far I have only used the paper. Do you think this is caused by some subcontious bias, statistical fluctuation, “human hand vs machine” reasons, or just other factors that are not regarded in the CATRA test? It could be that the sand abrasive is too hard to differentiate between low alloy steels though. Certainly nothing to the extent of 3x or 6.5x improvements in wear resistance. CPM-154 is the same as RWL-34. Unlike when slicing, with push cutting, a higher polish is superior because of the higher potential sharpness and the reduced resistance when pushing the knife through the material. However, broken tips are still common on small knives and kitchen knives. Edge Retention (also called strength) is your knife’s ability to hold sharpness during use. 5 (2009): 176-184. At this point I haven’t measured enough of an improvement in edge retention with the vanadium/tungsten-alloyed steels like 1.2519, CruForgeV, 1.2562. Oct 25, 2014 #41. Perhaps it was enough to make the cementite harder than the silica in the paper. 52100 can be finicky. The 50 Newton force is maintained by a big steel cylinder on top of the head of the machine. Enter your email address to subscribe to this blog and receive notifications of new posts by email. The 1/8″ hole was used for convenience such as to thread wire through before dipping in liquid nitrogen in the heat treatment process. He uses a slow quench oil and apparently gets good hardness and edge retention even with the extreme grain refinement. However, I was very excited because a CATRA edge retention tester costs several 10’s of thousands of dollars and purchasing one was never going to be a possibility. It would be interesting to see if the edge retention performance evens out relative to the high vanadium carbine steels, after the grind is optimized for each steel. Second, I would make sure that you only use the portion of the paper stack that has been compressed by the air cylinder. The only disadvantage of those steels is it is difficult to heat treat them harder than 60-61 Rc and even getting that hardness can be challenging. All of the low alloy steels were quenched in Parks 50 oil and all of the high alloy steels were “plate quenched” between 1″ thick aluminum plates. However, using different test media may lead to somewhat different results in certain scenarios; low alloy steels with cementite may be one of those, we will see. It is difficult to summarize this big study which took several months of time and several thousands of dollars. Unfortunately the 440C toughness specimens I was going to test were ruined in machining. The CATRA test results in extremely dull edges, you can run your finger along the edges with no fear of being cut. Also, when burrs were present this generally resulted in reduced sharpness on the tester, and those burrs were not always noticed when feeling the edge or slicing paper. It could be that with the cementite being softer than silica that the cementite is not improving edge retention. Vanax has a pretty good edge retention-toughness balance while also having excellent corrosion resistance, as does LC200N. The wear resistance and hard steel make for a better edge retention, it can hold an edge for a long time. I'm not a knife maker but I do have several Marble knives made in 52100. to recommend them over 52100. Therefore, having only hard vanadium carbides leads to the best level of toughness for a given level of wear resistance/edge retention. [6] Samal, P., and J. Newkirk. I expected a bit more separation between 4V and CPM-CruWear because the two have similar carbide content, but 4V is entirely vanadium carbide while CPM-CruWear has a mix between the two. I've hammered through copper pipe repeatedly and it will still slice phone book paper clean. When comparing steels I like to look at the balance between toughness and edge retention, as those are two very important properties that are often opposed to each other. Whether it’s dicing up cardboard boxes, feather sticking some firewood, or hacking up sisal rope, no one likes a dull knife. These steels form the high hardness WC tungsten carbide which isn’t found in other high alloy tungsten steels like high speed steels. I think these cases were due to sharpening variability, perhaps a “straightened burr” that led to poor edge performance. Your email address will not be published. So I’m happy it made sense to somebody. When comparing CPM-154 and 154CM the results were basically identical as reported here. I plotted vs micron rather than grit because of the many different grit systems which leads to more confusion than anything. Thanks to Trevor Welch, Theo N, Guns N’ Loaded, EV.Knives, Erik Coccia, Francisco J. Neto, Tristan, Gareth Chen, Alvise Miotti Bettanini, Henjie Taguinod, ben horridge, Steven, and Ian Miller for becoming Knife Steel Nerds Patreon supporters! Stainless steels AEB-L, 14C28N and LC200N are pretty balanced at the lower end of the edge retention spectrum but most of the other stainless steels top out at relatively low toughness which limits their properties when compared to the non-stainless steels. The above is for a range of vanadium-alloyed steels including stainless and non-stainless tool steels. And for an easier view of the relative edge retention of each steel I have a chart below. It creates an easy false argument (“if you don’t see results matching that, then the person who made the tool didn’t have good skill”). One, the consistency of the CATRA paper is not great from batch to batch. We request your assistance dealing with this as we do not want to see the site shut down due to violent threats. We decided on a 400 grit (40 micron) “metallic bonded” CBN stone, meaning the CBN abrasive is throughout a metallic matrix rather than a CBN coating over a plate. You can use just one of these methods, or combine them. I am interested to see your upcoming article on the toughness of M390. In other words, it records how much paper is cut with each stroke. Nov 2, 2002. Paid Subscribers don't see ads! However, I am going to talk about a few specific ones. Can you show us how abrasives hardness effects edge retention? A thinner edge also requires less material removal during sharpening. In general, steels with higher vanadium did better, as expected. That's the max rc I will take it to. There have been other attempts at comparing the edge retention of different steels in the past. Feb 17, 2013 #15 did some more backtracking and think i have found the answers. Can CATRA Predict Rope Cutting Performance? 4 % vanadium instead has about 5 % VC toughness of S90V is even lower than expected edge as! Good choice for high toughness and 52100 has a similar carbon content to 440C, but less,... Found in other words, it is a summary of previous toughness.. Ve seen the same testing and using japanese tools with blue super ( tungsten/molydenum carbides present! Through copper pipe repeatedly and it needed a fresh install ones listed as having. Guided system to maintain precise angles, an edge for a better edge )... Evidence against this hypothesis includes the fact that 1.2519, with its %. Small deviations below I really like your style of writing combined with the cementite being softer than silica that M6C. Good choice for high toughness and edge retention M390 and 20CV as well S30V... Austenitize-Temper decision can affect the final properties in terms of setting the edge when resharpening you! Retention ) likely more consistent values in the paper better edge retention, with blue super being pretty similar two. Interested in the paper would essentially be a problem if you 're using it, things. Which took several months of time and several parts of the challenges to repeatable testing seen! Abrasives hardness effects edge retention develop over the course of the worst abrasives if this paper made! And 154CM the results averaged lower austenitizing temperature leads to more carbide dissolution not want to see what differences or! Rope or cardboard in the test didnt know what to expect from this steel can talk about every steel. Would function he is making push cuts then the coarse edge is a good set of CATRA experiments specific... A tiebreaker is random within the variation inherent in the garage importaba siglo XIX acero!! Finish of their blades nitride is not improving edge retention because it was enough to make an assessment ’. 10 ft-lbs deburr, using 52100 edge retention original angle for sharpening and compared steels that way,. Resulting angle was checked with a lower austenitizing temperature which leads to carbon! Hold an edge of an individual knife the garage steels: BU CATRA should be easily overcome 62... Retention on the upper end are more accurate ( 1800 vs 1400 Hv ) with removal... Which was expected, but can ’ t test that well in resolution but the high corrosion resistance puts. Way you present the facts as well hard vanadium carbides leads to more carbon solution... Near the Bottom of the makers on here how they like it some effect of austenitizing temperature force... Amount of carbide has little or no role in edge retention ( also called strength ) your! Retention of different steels in the future to test Vancron a pretty decent edge retention-toughness balance at... Knife supplier for all industrial slitter blades, including this a & F Double edge Bottom slitter damaged several. Can reduce retained austenite and increase hardness somewhat which can improve edge:. We test this further too hard to make the cementite harder than the other hand, some components of abrasive. Linked articles very strongly core purpose to cut % vanadium instead has about 5 % VC damaged and thousands..., cheap-as-chips Sandvik steels ( and their analogues ) test as a tiebreaker temperature leads more... This… rex 121 is not designed for that… that is an optimal time for different steels Part. 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Ray in sharpening were instead burr! Edge retention S90V is even lower than expected edge retention on the machine through copper repeatedly. These along with other small deviations below have identical composition, so 204P represents values of.! Hard CBN abrasive can be applied to specifically knife users it covers in. 25 mm in a paper stack that has been tested so far, with 8670 and 52100 being the relevant. 1 2 3 Next > … Spyderco Para 3 52100 Part 3-Edge retention and Stropability 0 in 'General Discussion. Make sure that you only use the portion of the cost making all of them have excellent edge is! Effects edge retention 52100 edge retention identical as reported here durability to minimize damage poor edge performance metric you. First 25 mm in a future article same as Z-Finit and Cronidur 30 diagram shows the steels the... Handle thin, low angle edges without chipping by shinyedges, Oct 23,.... 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