Carbides on Cutting Edge

[Twindog]

The big difference is where we want to draw the line at "dull". If ya just gotta sharpen your blade when it starts to pull at yer arm hair instead of cleanly "wiping" every hair off effortlessly, you'd be better served by a low/no carbide steel. If you want a "working sharp" edge that may or may not take any hair off your arm, but will continue to saw through rope all day, you're better off with lots of carbides.

If we look at Ankerson's tests -- where he counts cuts down to a specific level of sharpness (still quite sharp) -- the high-carbide steels out cut the simple steels by a huge margin.

 

[chiral.grolim]

The big difference is where we want to draw the line at "dull". If ya just gotta sharpen your blade when it starts to pull at yer arm hair instead of cleanly "wiping" every hair off effortlessly, you'd be better served by a low/no carbide steel. If you want a "working sharp" edge that may or may not take any hair off your arm, but will continue to saw through rope all day, you're better off with lots of carbides.

If you are using your blade for soft, non-abrasive non-impact cutting, low vs high carbide makes no difference.
If you are using your blade where it may experience heavy impacts, low carbide is more ductile and will be easier (and cheaper) to repair.
If you are using your blade for a task requiring a uniformly razor-sharp edge, you may have an easier time achieving that edge with a low-carbide steel, but high-carbide can achieve it just as well with the proper tools/technique, and then it is a matter of experience regarding how long you can cut a given medium prior to dulling. Generally, to get the same cutting performance out of low-carbide steel requires reducing the bevel-angle below what is considered "stable" for the high-carbide steel, and that may not be a practical solution. *shrug*

Here is a link to a website for a company supplying cutting blades to paper-mills, it describes their different blade materials. The first is low carbide "regular steel", the last is sintered tungsten carbide, and those in the middle are high-carbide high-speed tool steels: http://www.jorsonandcarlson.com/services/technology/material_grades_guillotine_trimmer_knives.html

That's obviously a link to industrial use, and you can find many more such links with your own google-fu. In my own field, we use high-carbide microtome blades for a longer-lasting shaving-edge than low-carbide steel can provide.


In hand-held knives we may not need the performance of these tools, or may need a different kind of performance, namely a relatively inexpensive and easy to maintain cutting tool than can endure some amount of impact and edge-twisting (vs. machine-use), one that we needn't worry about snapping into pieces or having to send out for sharpening in order to have that wisp-slicing sharpness. SO NICE to be able to swipe that edge across a smooth hone and have it back to near-perfect performance It only lasts so long, but you can sure do a lot to it and still get it back with ease. Like with Ankersons tests of the Opinels - those suckers are cheap and REALLY easy to sharpen, and they can take a screaming edge! But they dull fast. But they sharpen fast too!!