Chisel alloys and wire edges - sharpening

[John C Cox]

Hey guys,

On my continuing quest to find one chisel to rule them all.. I am in the throes of working with various hardware store chisels.

I have noticed that some of them form a very persistent wire edge, some a medium wire edge that works out pretty easily, and some that seem to form no wire edge at all - sharpening just makes powder.

Of course - none of these guys say anything about their alloys other than "fine and dandy metal that makes all your dreams come true."

So... For you guys that know steel - what chisel steel alloys or grain structures tend to form a wicked wire edge and which seem to simply form powder.

Thanks

[Sean Reilly]

Most quality woodworking chisels today are made with A2 tools steel, older ones are O1. A2 steel will start to fail at less than 30 degrees, while softer O1 steel can hold a sharp edge at 20 degrees. A2 steel is harder and more brittle than O1, but if sharpened at 30 degrees or greater can hold that edge better/longer. Also, I'm not really sure what you mean by "wire edge", I'm assuming you mean sharp. Anyway, I would stick with A2 (most common) or O1 for woodworking.

[bridger berdel]

High chrome content seems to encourage the formation of a tenacious wire edge.

[ken hatch]

Hey guys,

On my continuing quest to find one chisel to rule them all.. I am in the throes of working with various hardware store chisels.

I have noticed that some of them form a very persistent wire edge, some a medium wire edge that works out pretty easily, and some that seem to form no wire edge at all - sharpening just makes powder.

Of course - none of these guys say anything about their alloys other than "fine and dandy metal that makes all your dreams come true."

So... For you guys that know steel - what chisel steel alloys or grain structures tend to form a wicked wire edge and which seem to simply form powder.

Thanks

John,

There ain't no such thing, but softer steel chisels can come close. A2 chisels are limited because of required sharpening angle and needing power grinding and water stones to sharpen in reasonable time. The best chisels are older soft steel or newer O1 that are easy to sharpen to the needed profile and/or angle for intended use and can be sharpened on almost any type stone. Because each use of a chisels will work best if they are sharpened to the optimum profile and angle for that use. That is easy to do with O1.

Of the modern chisels those from AI work very well and are not expensive, if you are willing to spend more, Japanese chisels are a bargain for what you get.

Of course as always YMMV.

ken

[Stewie Simpson]

These are made in A2 steel which is a very hard tough steel that takes a good edge. They do not in my opinion take as good an edge as a chisel made in high carbon steel. I have used high carbon Marple chisels for over thirty years and Norris plane irons for a similar time and I know this modern A2 steel is not as sharp.It holds an edge well but that edge is not as sharp. The other deficiency is that this steel sharpens in a way that does not help the beginner. Don’t be too fussed we can show you how to sharpen this stuff fine it’s just that high carbon steel will turn a burr and hone that burr off with ease. With A2 steel the burr comes away in tiny clumps and needs watching. (Reference source from David Savage.)

Link not provided;

[Derek Cohen]

Hey guys,

On my continuing quest to find one chisel to rule them all.. I am in the throes of working with various hardware store chisels.

I have noticed that some of them form a very persistent wire edge, some a medium wire edge that works out pretty easily, and some that seem to form no wire edge at all - sharpening just makes powder.

Of course - none of these guys say anything about their alloys other than "fine and dandy metal that makes all your dreams come true."

So... For you guys that know steel - what chisel steel alloys or grain structures tend to form a wicked wire edge and which seem to simply form powder.

Thanks

Hi John

In my experience, the blades that create the largest wire are those with the coarsest/largest steel grain. The worst offenders are A2 steel and steel with chrome to toughen it. Steels such as O1, but especially the PM steels (M4, PM-V11) create the smallest wire.

Having said this, there are ways to make potentially large wire edge manageable. Basically, what I do is simply ignore the wire from the coarsest stone (say 1000) and hone until the end (to the polishing stone, say 13000), and only at the end polish the back of the blade (with the 13000 only). The wire will reduce in size as the grit level gets higher. By the end it should be small.

Still the A2 steels have a "chewier" wire. It takes more back-and-forth work to remove it. That is a relative statement since I really do not consider it intrusive. A few more strokes and it is gone.

Regards from Perth

Derek

[John C Cox]

Bigger grain size.. That does make sense.

The worst offender is a fairly expensive German chisel (don't know the brand)... Some sort of very high carbon water hardening steel. But it makes a horrible wire edge.

The Buck Brothers (new production) chisels also make a pretty impressive wire edge until they are literally full hard. But the wire edge hones off fine.

The surprise is an Ace Hardware "pro series" chisel that looks just like the Stanley Fat Max except for no thru-tang. It sharpens nothing like the Stanley, though. The Stanley is apparently EN31 - which is a British version of 52100 - it feels gummy like A2 on the stones and forms a "normal" wire edge. That Ace Hardware chisel feels very dry and makes no wire edge at all. It doesn't seem like it is "sharpening" - but the edge gets very sharp. It just makes black dust.

The apparent hardness of the Buck, Ace, and the Stanley are similar out of the package - as neither scratches the other. Makes sense that the grain structure may be the correct answer.

[bridger berdel]

A2 is 5% chrome. That is a lot.