Good discussion guys
To extend the Heavy Duty discussion a little further:
I find myself prying semi frequently but never digging.
-Most commonly would be when trying to crack apart stubborn logs that are still stuck together after splitting.
-Also breaking down junk furniture for use as firewood. Hacking into a glued joint to open it up then twisting and prying to pop it or pull out any associated nails and fasteners- this can be quite intense loading on a blade.
A rat tail can do some of this work and you can isolate the shoulders of the tang (danger zone) by levering with the ricasso and bolster area rather than the actual handle. This limits overall leverage and also the depth at which you can pry things. I wouldn't really recommend prying with rat tails to others though as I feel like I have a pretty good gauge for what a rat tail can/can't take that others likely don't have. It's pretty risky, low reward business in that case.
I have done some very, very hard prying with my regent long knife and have bent the blades before the tang has come to any grief. This is to be expected due to the differential hardening process and softer spines and bodies similar to katanas. They can be bent back just as easily and are still plugging along fine many years later. A while back we instructed a customer to destroy a faulty regent bowie as part of a warranty process. He bent the blade to 90 degrees in both directions around a dozen times before finally cracking the knife. A fully hardened and tempered blade will have a higher amount of lateral stress it can take before it is likely to deform permanently, however that deformation is much more likely to be a sudden and catastrophic fracture. I feel that potentially there is value in a hard use survival knife for it to give you a warning short with easily mendable results before you overdo it. In chopping (vertical loads) the blade has a large enough section that bending under load is not a risk. In this application the reduced strain in the steel produces a blade with higher resistance to shock without any negatives I can think of.
Blades with thicker cross sections are a lot stiffer when prying and so are able to transfer more force into their target before taking on a bend. This is where the higher spine/grind thickness (even at belly) of the panawal, msi, scourge,falo and to a degree sirupate, HSI and angkhola come into play. They are much better at resisting such side loads than a m43 martial, regent bowie, mutiny or salyani (thick bolster but thinner forward spine region) for example. Shorter blades apply less leverage more safely and typically have less distal taper so are a bit tougher for prying.
The final heavy duty point of discussion is batoning. While this is a theoretically vertical load, in practicality it's easy for the force to come down at an angle, the blade to twist and for high lateral forces similar to prying to occur so thicker spines are safer. In batoning deep, narrow fullering is a risk factor. If you look at the blades cross section the fullering is a localised narrow section which is a lot weaker and more prone to bending than the rest of the blade. It's also located in an area of soft steel that's up near the spine being struck and so is more prone to bending under batoning than say the edge under chopping which is harder and less likely to yield. As a result Mutiny, salyani and pensioner have enhanced risk in these scenarios despite more moderate spine thicknesses. Light batoning should be fine for them though. Tin chirra are thick enough that it isn't such a concern. EK chirra is broad enough that the force isn't that localised. Dui chirra is a little of both.
Take care,
Andrew and the team at Kailash
). I'm sure it'll involve some ground level chopping and hacking through the roots while I've got tension on the chain with my truck. I expect some edge dings on the khukuri but I should be able to repair and sharpen the edges with my axe pucks, Fallkniven DC-4 and possibly my Spyderco stones.