Spyderco Forums

do you have any good sources or papers on the cutting force approximation you described? Its a first order hook's law approximation, most materials tend to obey it, especially in small displacements. Beyond that it gets very material and cutting specific. "Modeling of cutting by means of fract...

It is just the transition point where the edge bevel meets the blade bevel and it is only one measurement of the blade geometry, it doesn't describe the entire geometry. For some cutting it isn't even the critical aspect. As the force on a knife decreases away from the apex and falls off rapidly to ...

So (assuming I'm reading everything right) why bother with TCE as your unit instead of just using material cut and noting that cutting proceeded until performance was 1.5% of optimal? Because that number is very unstable because blunting is not linear. Here is what the sharpness actually looks like...

Title says it. What are your thoughts? Don't use hardness as a means to judge how to harden steel. -- There are a few general ways to approach it based on what you are trying to achieve : -If you want a balance of strength/toughness/wear resistance then soak just enough to put ~0.6% carbon in solut...

Archimedes wrote:Run it up to the high 60's. 68-69. Push the steel a little.

It would take some pretty demanding cycles to get 69 HRC in 52100.

Regarding the first question about the edge retention scale, I still do not understand. Are you saying that the numbers on the left are a percentage? A percentage of what? The highest edge retention in any one of the runs with any of the blades, it was one of the 66 HRC runs. And what two knives ar...

What does the "Edge Retention" scale tell us? It is edge retention slicing hemp on a 2" draw, I did five runs with each knife, measured the sharpness two ways. It took a massive amount of rope, I went though an entire full roll. I normalized it to make it a percent as at the time I f...

1095 at 67? Never mind............ I have knives at 1095 at that hardness, they were made by Alvin Johnston and hardened so as to produce maximum strength. 1095 actually can have a slight increase in hardness during tempering if the temperature is low (~325F) because of the strong precipitation of ...

Is there any deformation or damage to the lock bar face or the blade tang, is there any play in the blade?

clevelanddean wrote: Need some guidance other than just sending it in....

When you open the knife how much of the bar engages the tang?

Not sure why its so hard for you to see? I never said that the way a blade is hardened doesn't influence its material properties, what I said is that the HRC result isn't a meaningful way to quantify that. As for the kind of spread seen in performance reports, the dramatic differences often describ...

MCM wrote:I wonder if your Domino ...

It can't it isn't obvious, I am not the person in the video.

I have to think M390, 204P and 20CV should test out pretty close with identical grind and optimum HT.

I would hope so since they are the same steel just made by different manufacturers.

All I am saying is a certain steel with a RC of say 56 is going to perform differently than the same steel at 60. Yes, it would be different but how different isn't trivial to predict. I have posted up papers here showing that even though the hardness in a steel can increase the strength can decrea...

To make these tests more accurate, I wish the HT numbers were posted. The hardness numbers? These are useful but care has to be taken in interpreting what they are measuring. The Rockwell machine was designed, and still is intended to be used for a quality control check. If you run a particular set...

From what I can see the grind is the same from the tip all the way to the ricasso but the sharpmaker just won't hit the edge near the tip. Hmm... That is most likely the problem because what you probably mean is that the edge width is the same? If the grind of the knife (the taper) changes towards ...

It's it at least theoretically possible that all the stars have aligned and the knife is on the lower end of the HT, and the carbide distribution in the portion of edge that's currently exposed is unusually low? It is always possible that almost an infinite number of things can bias the results thi...

The next sensible step would be to contact Spyderco. if the blade is defective, which seems likely, then there is no reason to just accept that and what has been done is a decent argument pointing towards a possible problem : -general use indicates lower than expected edge retention for 204p -repeat...

Update :

https://youtu.be/4gnej8hJXAo

As expected, the performance of the 204p seems likely to be restricted to that knife as the Elmax blades falls about where you would expect, between S90V and ATS-34 in a high wear based test.

I have most experience with VG10 in Delicas and Enduras. I like it and appreciate the price point, but it definitely dulls much sooner than 204p on poly rope. That is what I would expect on high abrasive wear applications, and it is the curious thing about Michael's comparison. He is interested in ...

1. Apex profile, s90v is flat vs curve for other 2 knives. bottom of the curve subject to tiny more impact vs where flat is evenly distributed. 2. Sharpening - ceramic & strop steps are questionable. Passed hht doesn't mean much except this keen (thin apex radius) could be weakened along way to...