Wire Edge?

Joined
Oct 27, 2006
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Noob question. what exactly is a wire edge, what causes it, and how does one get rid of it?

Sorry if this is a repost but the search function wont work :mad:
 
A properly honed edge will form an edge shaped like a perfect V.

Some combinations of steel and sharpening technique result in an edge shaped like a Y or y. That sliver of thin metal beyond the V shape is called a wire edge.

The wire edge is essentially a thin foil, useless for any typical cutting tasks since it has no strength. It will fold over, break off in sections or both, resulting in an instantly dull edge.

The wire edge can be difficult to grind away, since the thin foil tends to flop from side to side - bending away from the stone - rather than grind away cleanly.

One technique for removing the wire edge is to slightly increase the final bevel angle a few degrees, alternately honing both sides with low pressure until you cut the wire edge away from the V.

Difficult to describe without graphics - hope this helps!
 
The wire edge is your enemy! gud4u explained it well, and I recommend getting a lighted microscope (60X-100X at Radioshack for $9.99), and you will be able to see what is going on with your edges. That improved my sharpening tremendously, and gives you a much better idea of what is going on with the edge.

Mike
 
I gave my daughter one for Christmas this year. Excellent value... plus dad uses it once in a while to inspect knife edges :)
 
A properly honed edge will form an edge shaped like a perfect V.

Some combinations of steel and sharpening technique result in an edge shaped like a Y or y. That sliver of thin metal beyond the V shape is called a wire edge.

The wire edge is essentially a thin foil, useless for any typical cutting tasks since it has no strength. It will fold over, break off in sections or both, resulting in an instantly dull edge.

The wire edge can be difficult to grind away, since the thin foil tends to flop from side to side - bending away from the stone - rather than grind away cleanly.

One technique for removing the wire edge is to slightly increase the final bevel angle a few degrees, alternately honing both sides with low pressure until you cut the wire edge away from the V.

Difficult to describe without graphics - hope this helps!

Thanks, exactly what I was looking for.

and I'll be looking for a microscope...
 
The wire edge is your friend.
It's nice when the wire edge shows up when you are looking for it, and then it's nice when it goes away.

When I take out my stone and begin to sharpen, I use the system that is suggested here on this forum.
Where I sharpen only one side until I can feel the wire edge apear on the flip side of the blade.

once I have a wire edge the full length of the blade I turn the blade over and sharpen that side, again looking for a wire edge .

The wire edge is telling you that you have sharpen one side so much that the thin edge is curling over and thats what feels like a wire.

Unless you get a wire you are not getting the edge really sharp.

once you get a wire on the 2nd side, then you have to do the more traditional style of stone sharpening where you flip the knife around at every pass on the stone...this will cut the wire and leave a shapened edge
 
The wire edge is a signal that sharpening is nearly complete. Just alittle more at the sharpener now to get rid of it. Wire edge is a waste byproduct of sharpening. Too much wire can mean improper sharpening such as using too much pressure and sharpening too long on one side. It can also mean improper heat treat if wire edge forms too easily during sharpening.

I get rid of that bit of wire edge using the V sticks or butcher steel to set the final edges.
 
I personally try to avoid creating a burr, but that's just me. I know a lot of others create the burr to be sure they are getting all the way to the edge, then flip sides and hone to a burr on the opposite side, then get rid of it. I also cut straight into the stone if I have used my knife hard to remove all fatigued steel, and that helps to cut down on burr formation also. I just slice lightly into the stone (very lightly) until all of the damaged steel is gone. Cliff Stamp mentioned that trick and it works wonders for cutting down on burrs. I just prefer to not get a burr in the first place, but sometimes you can't avoid it. When one pops up I use Jeff Clark's method and raise the angle to be sure I completely cut it off, then lightly hone to reset the edge. I'm sure someone more computer savvy has the link to the post, I have it printed out somewhere. There are some steels, all of the AUS series as heat treated by CRKT come to mind, that are very burr prone, and a pain to get a clean edge with.
 
Just a tip I use...

I sharpen my knives on the Spyderco Sharpmaker. Before I begin, I take a sharpie marker and color the current edge of the blade. This way, I can actually see where I am getting to the edge and what needs more attention.

It helps to prevent a wire edge from forming.
 
I've found that the best indicater of a wire edge is feel. The edge will feel sharper, but also rougher, on one side of the blade.

Sometimes you can see it without magnification, but you can generally feel it.

I would agree with the assertations previously made that this usually occurs as you are about done. What I've done before is just run the blade lightly through a V-notch sharpener a couple of times then only take one lick at a time on each side of the blade.
 
gud4u did a particularly nice job of describing a wire-edge (aka burr). Let me add a little bit to that. The burr is metal left over when you hone past the previous margin of your blade. Ideally the length of the burr indicates the excess depth you honed into your blade beyond the minimum to form an apex. Theoretically the longer that you hone the longer that your wire edge could become.

If you were honing an extremely hard and brittle material like glass you wouldn't get a burr (you would get little chips in the edge, but that's another story). The ductility of the steel that lets it bend plastically and not break also helps the burr to form and not break. If you have a tough blade it is somewhat more inclined to form a burr than a brittle blade. It also seems to me that chrome in stainless can exacerbate the problem. Burr formation is greater when you hone at low razor-edge angles. If you continually hone at the same low angle the burr is not removed. To cut off the burr you need to do a little light additional honing edge-first at a somewhat higher angle. How much higher that angle is depends on the steel. On a really troublesome alloy I sometimes go all the way up to 45 degrees for a few strokes. On finer-grained alloys I sometimes only increase my honing angle by 5 degrees (say from 10 degrees up to 15 degrees) for my deburring step.

It doesn't hurt too much if you have to deburr at 45 degrees if you follow up by doing a little additional honing at your normal angle. I might hone at 10 degrees, deburr at 30 degrees, then hone a little more at 10 degrees, and finish with the slightest micro-bevel at 12 degrees. When I am done there is no trace of the 30 degree deburring and you actually can't see the 12 degree microbevel either. The edge just looks like 10 degrees.
 
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