Edge chipping/rolling/deformation

R

rayback

Joined
Sep 16, 2006
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I was reading in the forum, that there are some steels which suffer from edge deformation when cutting soft materials like cardboard, rope etc.
My plain logic says that soft materials as these, should be the easiest cutting task for a knife steel to accomplish.
Which steels suffer from this problem and why?

Thanks
Ray
 
Im sorry to say I dont have too much experience, but I have a delica in vg-10 that has com in contact with some hard sufaces more than once without chipping. On the other hand I have a Benchmade Rukus with a very sharp blade, hair poping sharp. I was chooping wood with it, middle of nowhere and no other tools (should have used somthing else) when I slipped and it nicked a rock right in the belly. Four little nicks in the knife, but fortunately i was able to clean them out with a stone at the house.
 
rayback said:
Which steels suffer from this problem and why?
Click to expand...

Inherently there is no cutlery steel which can't cut those materials without harm. Generally steels which suffer from problems cutting those types of materials would be considered to be defective.

-Cliff
 
cardboard is especially hard on fine edges. it is often made from wood pulp containing misc materials like bits of metal and such. with a very fine edge, the metal is so thin that it may roll when cutting, but not chip. i prefer a steel that will roll, generally speaking, because i can usually repair it since no metal is gone.
 
When I asked which steels suffer from cutting those type of materials, I meant to carbides and the grain size of the steel.
How these two elements related to cutting those materials? or how will they affect the performance of the steel when cutting such materials?
 
It is going to depend on how you are doing the cutting and the type of finish. If you polish the edge highly and do mainly push cutting then you want a very fine carbide steel to keep the edge very sharp. These are steels like 52100 and AEB-L, they have a small amount of very small carbides.

As you move towards steels with more carbides like D2 and 154CM they don't work as well with higher polishes because the carbides will be torn out of the edge as it wears. Those steels will do better with more coarse finishes and slicing the same materials. As the carbides tear out it will leave jagged patches which can enhance the slicing ability somewhat.

-Cliff
 
The problem you mention is almost certainly not with the steel, but instead with the manufacturer and their heat treatment of the steel.
An edge that rolls from cutting soft materials (cardboard is abrasive but not hard) demonstrates that the steel wasn't hardened enough to begin with, or was annealed by improper tempering. Either way it's the HT that the maker is messing up.

Rus
 
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