Thread: PM-V11 chisel

There is a myth that circulates that chisels - or any handtool with a blade - are ready-to-go out of the box! All these blades are sharpened by a machine and not by a human. I really would not expect anything better than second best .. at best. The first thing I do after receiving a new chisel or plane blade is to grind the edge to the angle I prefer, and then hone the blade of stones of my choosing. This is likely to be quite different from the decision made at the factory.

I suggest that you sharpen the chisel and try again. The current image indicates that the edge was dubbed.

Regards from Perth

Derek

Looks like the powdered metal isn't quite consolidated.

Rob, that could be from heat treatment of a thin edge. It is more brittle as a result, and benefits from being ground away.

Regards from Perth

Derek

The appearance of the chisel shown above reminds me of micrographs presented in V9 Metallography and Microstructures of the ASM Handbook (1985) on page 99, Figures 34, 35 and 36 showing the progressive sintering of metal powder spheres.

Decarburization, if that is what you mean by a heat treatment effect, is generally visualized following acid etching (50% aq. HCl) of polished specimens where decarburized areas appear lighter in color than non-decarburized and it is often visible with the unaided eye. A nice description and images are presented on pages 174 and 175 of the same volume. Unfortunately all copyrighted.

P.S. Slides #30 and 31 of this presentation (https://www.slideshare.net/awad1991/...metallurgy-2-1) respectively show a schematic and images of what I mean regarding the progressive changes in powdered metal structures.

Originally Posted by Ilya

Bought a Veritas chisel made from the highly praised PM-V11 steel. As some may have guessed, I took it to the microscope before first use. Here is a couple of images. First one is of the edge (facing from the flat chisel side). The edge appears quiet rough, with roughness of the order of 5-6 microns, a bit disappointing as this is noticeably worse than what I get in my kitchen knifes after 3 minutes of sharpening as I recently posted on the forum. So the chisel edge can definitely benefit from honing on those lapping films that Lee Valley sells.

Interestingly, it seems that the flat side of the chisel is not flat towards the cutting edge. About last 10 micrometers go at an angle, so the tip is more like double side sharpened knife.

10 micrometres is equivalent to 1/100th of a mm?
This will disappear when you sharpen the chisel before first use.

I would be more useful to report edge roughness AFTER initial sharpening and honing.

Originally Posted by ian

10 micrometres is equivalent to 1/100th of a mm?
This will disappear when you sharpen the chisel before first use.

Yes, 10 microns is 0.01mm. And yes, this is the aim to hone it to make sharper.

Originally Posted by ian

I would be more useful to report edge roughness AFTER initial sharpening and honing.

Do not quite agree with this - the pictures show what hundreds or thousands of people will be getting right from the shop when they buy these chisels (assuming that LV has consistent production quality). After I hone the chisel, it will show just my ability (or lack of it) to make a good edge.

Just to clarify a bit my actual impressions - the chisel is actually quiet sharp and usable in my view right out of the box. Would not shave hair though.

I am planning to add photos once I get to hone the chisel and hopefully get a better result

No Ilya. What the photos will show after you have honed the chisel is the ability of the steel to take an edge. After all, what is relevant is the chisel's ability over time - not as a virgin. Let me repeat, no one is expected to assess and evaluate a blade out-of-the-box as if it was ready to do its best work. That is unrealistic.

That your chisel does not shave hair - which is a silly test - just goes to prove it is not working sharp.

I tell you what - go and sharpen the chisel the way you would use it, and take some more photos for us. Show us what you get.

Here is a PM-V11 chisel I honed and used ...






If your honed chisel cannot do the same, then it has a problem.

Regards from Perth

Derek

Thanks, Derek. I'd be surprised if the chisel will not do these end grain cuts easily after honing - even my cheap Bahco chisels do this easily after I hone them on LV diamond films. I suspect that the main advantage of Veritas is that it will hold the edge longer. Maybe I will hone the Bahco and PM-V11 as well as I can, then look at them under the microscope, then use them to do similar cuts, then take back to the microscope and see if I can see any difference.

Hi Ilya

I like that idea. Try and count how many end grain cuts each can do. Aim for the same thickness shaving, etc.

Here is a comparison I did: http://www.inthewoodshop.com/ToolRev...sCompared.html

Regards from Perth

Derek

Thanks again, Derek. Excellent comparison of chisels (I now recall seeing it a while back, but totally forgot!). Not sure I will be able to do similar comparison, as I am not doing this much work with chisels, but will do my best with some hardwood offcut.

Hi Iyla

One thing you could measure out of the box is how square the edge is and how flat the back is.

Finally got around to do some rough tests. So I sharpened my old Bahco and and the Veritas. Without fanaticism, but going through the diamond lapping grits as I would normally do, pretty quickly. The photos of them sharpened are:

Veritas:

PMV11.jpg

Bahco:

Bahco.jpg

They actually look like a pretty decent mirror, and I had to find a certain angle for a photograph to see the bevel. So it looks at this angle scratched more than how it appears in real life. For the tests, as it turns out, I chose wrong timber - I had very dry and extremely curly piece of blackbutt lying nearby and I used it. It is tough, so I couldn't make very consistent shavings across the grain. And the chisel angle of 27 degrees is not ideal for such tough wood, so this is not an optimal test. Making cuts, even non-uniform, leaves smooth shiny surface (but uneven as I couldn't push straight through this timber). The shavings look like this:

shavings.jpg

Finally, here is the comparison under the micrioscope: after sharpening (top row) and after doing 20 cuts (bottom row). The quick sharpening is not perfect, with about 3 micron roughness. By the feel, though, this is very sharp, you do not need to press at all to shave hair. They both cut softer woods very pleasantly. After 20 cuts both chisels show that the tip is bent, with the burr estimated at about 5-10 microns, probably a bit less for the Veritas. At the same time the Veritas also had much more uneven surface after cuts - with large dents all across the surface. Maybe because it is more brittle.


2Chisels.jpg

I haven't found any direct reference to the specific alloy used in the Lee Valley/Veritas PM chisels but I have found data (ASM) for the similarly designated alloy PM/CPM-10V (:rucible Industries:: Our Products - eSelector). Most of the physical tests results such as scratch, cylinder wear, notch and hardness, carbide content and crystal structure are similar to D2.

Excellent work Ilya. It really does highlight the unscrupulous BS factor that's being fed by others on the merits of these new high alloys steels.