Bob Kramer Video

[Eamon Burke]

His knives are not heat treated to pass that test. They are heat treated to perform well in a kitchen...the knives that are used for the bend are also used for other tests that show high levels of competing characteristics--it is an attempt to assess one's control over a medium.

[Crothcipt]

Ya never told him that. I have learned that reading this thread. I wont tell him either have to let him suffer more.

[jmforge]

The grind of the blade, particularly the taper, can have an effect on how the blade performs in the bend test. My failed blade was event tapered and bent in an almost perfect arc before it snapped right at the vice jaws. The spot of large grand that caused it to fail was actually in the "soft part of the blade. Others I have seen pass have taken a set right at the point where the vice jaw contacted the blade and even after being released, still have a sharp bend of over 45 degrees. In the case of a knife like the Kramer, the fact that it does have such a thin, tapered blade can allow it to bend more like a spring and snap right back even at higher hardness. Some of the traditional Mexican "singing" swords, which are naturally "softer" than the typical 52100 kitchen knife, can be bent around 180 degrees and they come back to straight. Like I said before, the trick with the Kramer knife was that is survived the 2 x 4 and bolt cutting tests and still appeared to have a sharp edge. The rope cutting test is probably the easiest of the three tasks. The 2 x 4 chop is not that bad either. You can't whittle, but there is no time limit to the test, so you can go slow and easy. The bend is where most people fail.

[Bill Burke]

It is My sincere belief that any of the knives that Bob makes will pass all of these tests with the exception of cutting the Bolt. It Is also My belief that a properly forged and heat treated blade <.100 will bend 90 and return to straight at a hardnes of ~61 hrc. I regularly test my knives in this fashion And I know that Bob does also. The exception, Cutting the bolt can also be done but requires a thicker edge that is not desirable on a kitchen knife.

[jmforge]

Good point, Bill. But the bolt cutting knife in the video is still quite sharp by normal standards, just not by crazy kitchen knife standard.

[Bill Burke]

Good point, Bill. But the bolt cutting knife in the video is still quite sharp by normal standards, just not by crazy kitchen knife standard.

I agree that it is sharp but if you pause the video and look at the edge it looks like it has pretty obtuse angles on the edge for a kitchen knife. I do imagine though that it is still very sharp and you could use this knife in the kitchen with no problems.

[jmforge]

Bill, perhaps one lesson that can be learned from that demonstration is a confirmation of what some guys like Roman Landes have been saying for a while. Assuming proper heat treatment of a number of the good carbon steels available today, a lot of people tend to leave them tempered softer than they need to be, much softer in some cases. The edge geometry on that particular knife may be less that ideal for a kitchen knife, but as best as I can tell, the edge not only didn't chip, but it also didn't roll or dent like it might at the considerably lower levels of hardness that some consider ideal for a "tough field knife". Food for thought at a minimum.

I agree that it is sharp but if you pause the video and look at the edge it looks like it has pretty obtuse angles on the edge for a kitchen knife. I do imagine though that it is still very sharp and you could use this knife in the kitchen with no problems.

[Bill Burke]

True Jim,
I don't understand why people think that they need to temper their steel back into the fifties. My hunters are 60-61 and my kitchen knives tend to run about 63.

Bill, perhaps one lesson that can be learned from that demonstration is a confirmation of what some guys like Roman Landes have been saying for a while. Assuming proper heat treatment of a number of the good carbon steels available today, a lot of people tend to leave them tempered softer than they need to be, much softer in some cases. The edge geometry on that particular knife may be less that ideal for a kitchen knife, but as best as I can tell, the edge not only didn't chip, but it also didn't roll or dent like it might at the considerably lower levels of hardness that some consider ideal for a "tough field knife". Food for thought at a minimum.

[Eamon Burke]

Got to agree there. I had a folder with a blade that was about 61 and it was a lot better to deal with than the ~58 I have now.

[jmforge]

As far as I know, I haven't sold a knife made from 1084FG or W2 that was any softer than 60RC at the edge since i got my Paragon oven and first bucket of Parks #50 a few years back. The only time that I have been tempted was when using Cru Forge V because it hand sands a lot easier at 59-60 than at 61+.:big grin: If someone wants a big chopper type knife, I use W2 because I know that the interior of the blade at the thicker parts like the spine will naturally be a bit "softer" because of the shallow hardening nature of the steel. Randall may be the biggest offender as they appear to still leave their O1 knives at 54-55 cuz dat's da way Bo did it in 1938, but you do see a LOT of production tactical knives made from 1095 at 57-58 and claiming some "ultimate proprietary heat treatment"