Foreign vs USA steel grades, vs sharpening tools

[GIPPER]

Admittedly, I don't know very much about steel grading systems, especially between one Country and another.  But I sure am curious to know if steel grade material from, say China, could be the cause of my not being able to sharpen a chisel tool made in China, yet be able to sharpen an identical tool made in the USA perfectly?  I mean no disrespect to any of our Chinese friends.  It just happens to deal with products made in your country.  Gipper

[Herman Trivilino]

If it's carbide steel, that would make it much more expensive, and much harder to sharpen.  Of course, it'd be a much more durable edge.

[GIPPER]

Hi Herman. Thanks for your thoughts.

I doubt the tool in question, a square 5/8" carving gouge, is made of "Carbide Steel".  Carbide steel usually contains Tungsten and used in making drill bits, steel cutting and finishing tools, etc. which are subject to high temperatures.

Instead, I think I need to focus more on the tool itself, and my own skills and techniques for sharpening this rascal.  I did find it to be non-square to start with, as well as dull.  I went through the "Line of Light" process, which I call the "Daylight Method", first by squaring the edge.  I found there was increasing "daylight" from the center to the outer edges of the tool, both left and right sides.  I grinded these down to an equal "line of light" around the edge perimeter.  Then I completed the grinding by complete rotations of the tool, on the stone, from left to right.  Fine grind and honing followed that.  The tool was still not "sharp" so I tried again.  Same results.  The bevel face is pretty shinny but I can still feel a few "saw tooth" notches in the edge when tested with the edge of my fingernail.  And it will not cut wood as cleanly as I would like to see, especially when cutting cross-grain.

Other than that, the grinding efforts seem to be no different than grinding U.S. grade Cast Iron which I think this tool is probably made from.  I would love to see a video on how this tool was made, from the foundry to the shop.  Gipper

[Herman Trivilino]

When you finish grinding do you have a burr on the flat side?  If you don't, then you haven't ground far enough to form an edge.  If you do get a burr, then it could just be that the steel is inferior and won't hold an edge.  You might try grinding at a more blunt angle, and use this chisel strictly for rough work with a mallet.

[GIPPER]

Hi Herman.
Thanks for the comments.
Funny thing about it, when I hone the burr off the flat side, the burr appears back on the bevel side.  Hone that down, it appears on the flat side.  Kinda like a dog chasing its tail.  By the time I do get rid of the burr, I can see that I now have a "rounded" edge.  That's what got me wondering about the grade steel the tool was made from; maybe too soft.  Gipper

[ionut]

Hi Gipper,

It may be the grade of the steel  but I think is more the grain of the steel, the grade would be related to edge retaining properties, the grain would be related to the quality of the edge.
Chasing the burr few times is normal, if it takes you a long time to get rid of the burr, it is not. Make sure the stone is graded properly close to 1000 so the burr would be smaller and easier to remove.

Ionut

[tb444]

It depends on the steel - different alloying elements will affect the grain size, carbide type and distribution, and also on the heat treat of the steel as to whether it will stay sharp. Any steel should be able to take a sharp edge-who's cut them selves on a baked bean can?
The burr removal seems to be the problem you are having which again depends on the alloying elements and the heat treat. The amount of burr flex you are experienceing suggests the steel is quite soft so i wouldn't expect this chisel to ever take a good edge but it should get sharp. One method of burr removal you could try is to slice the edge through the end grain of a pice of wood-as though slicing with a knife. This should pull the burr of, and you can then refine the edge on the leather wheel.

The toothiness you mention, may be due to the steel having very large carbides, which as you sharpen are getting ripped out, leaving behind the soft matrix which won't support a sharp edge.