Newly sharpen chisels dulled first use

[Bob Glenn]

I spent the afternoon sharpening a set of chisels that I bought in an antique shop a few years ago. I was going to be cutting some dove tails for a toy chest and wanted sharp tools to work with. I put a 20 degree angle on all the chisels with my Tormek grinder and honed the edges.

After sawing the tails, I started to pare to the line and noticed immediately the freshly sharpened chisel appeared like it had been dropped on the floor. The cutting edge looked chipped. I am working with Southern Yellow Pine, which is harder than than the yellow poplar I usually work with.


I thought maybe the chisel was bad, but others did the same thing. Is a 20 degree edge too acute, or is SYP just too hard? I've had to break out my router with a dove tail bit to clean up the tails.

Any advice is appreciated.

[john brenton]

I'm sure I've had angles going all over the place before I got a jig and paid attention to it. If it looks like it's too steep then it probably is. Why not just do the traditional angle?

Wood is different, and some wood of the same species is harder than others...but I know I use SYP all the time and my tools don't get beat up like that. Are your other chisels good quality?

[Bob Glenn]

I don't know how to assess the quality of the these chisels as I have not really used them up until now. Most of the set are stamped R B C Waranted, and one is stamped PEXIU. What do I have here? Both have chipped.

[john brenton]

I have never heard of those brands. Maybe a pic would help?

[george wilson]

Sure it isn't PEXTO??

[David Weaver]

I would guess pexto, too. I have a couple of pexto chisels. They are similar in quality and the steel seems similar to stanley 750s.

Compared to Buck chisels, which seem to be finer steel (they take a really excellent edge), but also softer. Maybe a "plainer" alloy.

I don't know what RBC is, but if it has a Warranted stamp, it should be decent steel unless someone has ruined it on a grinder.

it's likely that both will hold up much better and be fine at 25 degrees.

[Chris Fournier]

Some machine shops have Rockwell Hardness Testers and for a small fee they could tell you what the Rc. of your chisels are. This aside, 20 degrees is truly at the thin edge of the wedge and any chisel that I've sharpened to 20 degrees has chipped in use very easily. I used a chisel sharpened like this to pare sitka spruce braces on acoustic guitars and it chipped pretty easily so your yellow pine would be even tougher on such a fine edge.

[john brenton]

Ahhh, PEXTO. I didn't even think of that. My mind went straight to some kind of European manufacturer.

[Mike Siemsen]

Try honing them to a steeper angle of 25 degrees, if they still chip try 30. 20 degrees is usually for a chisel that you push by hand alone. Be sure that you only chop straight in with the chisels, do not use them to pry out the waste, prying out the waste can chip the chisel.
Mike

[Bob Glenn]

Yes, it is probably Pexto, however, it looks like the stamp didn't carry all the was around the hosel of the chisel, thus and IU instead of TO. I'll hone to 25 degrees and try that. Thanks

[JohnPeter Lee]

+1 on a steeper angle.
I've been able to work with a ~22-degree bevel on my old Greenlee and Douglass chisels, and that seems to work well for paring cross-grain on dovetails.

JPL

[Frank Strazza]

20 degrees is the problem, you definitly need to sharpen up to at least 30 degrees or so, especially when chopping that yellow pine. Just think when you are paring wood you are only applying about 10 pounds of pressure to that chisel edge, on the other hand when you are chopping you are applying about 80 pounds of pressure to the edge.
By the way don't get wrapped around the axle to much on the angle, just go put a secondary bevel on the chisels and you should be fine. Yellow pine is tough on tools so you will need to sharpen often too.

Good luck and may all your dovetails be tight!

[Charles McKinley]

Wouldn't the hollow grind of the Tormek give you an even thinner edge than the flat bevel from a stone?

[David Weaver]

Not by much.

You can do the geometry with autocad or something, or even by hand, with a circle with a 5 inch radius for the tormek wheel.

The hollow is very shallow.

If it is a concern, you can add two degrees.

There is a lot written about how weak a hollow ground edge is, but for the most part, people who hollow grind hone their chisels on stones, and I haven't ever had a hollow ground chisel break back to the hollow. I've obviously chipped edges like everyone else has, but they have never gone through the honed are into the hollow, so for practical purposes, I am not going to adjust angles (even on a 6 inch grinder) until I actually see a failure.

My experience with japanese chisels is they are also fine off of a tormek (because of the large radius), they are just ugly to look at if they are sharpened that way, and it is nice to freehand hone them to encourage thrift with the edge.

[Andrew Gibson]

This is a little off subject, but I have a set of Crown chisels from woodcraft, that I have had sense starting into woodworking. I grind to 30* then micro bevel an extra 2* or so. Using them to cut dovetails for drawers out of QS sycamore and maple, the edge roles over like a scraper. I keep thinking maybe a little more grinding and sharpening and I will get back to better steel... the edge even rolled on the 1/4" chisel I used to pare out the corner waste on the half blinds.

I am hoping to Pick up a set of LN Chisels at the upcoming show... I have been lusting after a set of them for nearly 2 years...

[John Coloccia]

There's a reason I don't own any Crown chisels, Andrew...

The Pfiels at Woodcraft are nice, though they're not my favorite for chopping dovetail waste.

[george wilson]

I have said this before: I read that some chisel makers have started making their chisels softer because of fear of liability should one chip and get a steel splinter in the user's eye.

I bought a pair of Crown skew chisels years ago to make planes with at work. They seemed hard enough. Maybe by now they have joined the ranks of those making them softer. I have no new ones to compare at home.

I know my old 1965 Marples are plenty hard. I still use them. In 1970,I had 3/4" of the widest chisel(1") break off. I wasn't even stressing it that much at the time. I still use them. I checked the hardness of the Marples I had at work,and they were fine,but NOT of recent make.I have a few other sets,too,but none of them are of recent manufacture. I know the Sorby
LATHE chisels at work were way too soft. I actually had to reharden some of them. They were NOT of recent make,either. By now,they must be about 30 years old. I have steered clear of Sorby chisels since then.

[John Coloccia]

I had a number of Crowns that I've gotten rid of after acquiring my LN. It wasn't they they were all bad or all good. It seemed very hit or miss. One was OK, another had cream cheese for an edge, etc. It's too bad there's no way to test them in the store as they otherwise seem like decent chisels.

[george wilson]

Just wipe them on a bagel,John.:)

[David Weaver]

George - were those lathe chisels carbon steel or HSS?

I've been kind of nonplussed with sorby stuff, but haven't gone further with the chisels than looking at them in the store. They are as expensive as ashley iles chisels, which are of the same pattern, are harder from accounts I've heard and are finished much better. Those are good chisels, but if they were as hard as LNs they would be chippy. They seem to hold an edge about as well as "old" chisels in terms of use between sharpening - they are not near the quality of the steel in japanese chisels (any that i've tried in white #1,2 or blue #1,2), but they are still good chisels.

I would really like to see a western manufacturer make some bench chisels out of Blue #1 or cutlery blue with a mild steel or soft iron backing. Or maybe some of the new powder metals in profiles a hand tool user would like (delicate bevels).

[David Weaver]

One aside - the two nicest steels I've played with that don't feel exactly like O1 or A2 are pfeil bench chisels and two-cherries chisels.

both of them are not like I would like in terms of grinds, balance, handles, but the pfeil steel feels closest to "old steel" and takes a really good edge, and whatever the two cherries steel is, it's very tough, and if you're not using oilstones, you can get it plenty sharp. When I had some hirsch/TC chisels (no longer do), I didn't have oilstones, but I would imagine the two-cherries chisels might feel gummy on them and be noticably less sharp than O1 or old cast steel comes off of oil stones. They were long and tippy, though, and the pfeil chisels are like a lighter weight version of the same balance, though a little nicer to use, and may be very nice with the sides ground down delicately (why can't they just do that at the factory?).

[john brenton]

I got a set of Footprint chisels with the blue plastic handles on craigslist a while back and they are fantastic, especially for the price...but not EXCLUSIVELY for the price. Meaning, that even if they were more they'd be a good set. (Of course I paid next to nothing, or I never would have even considered a chisel without a wooden handle).

But really, for paring or chopping I've found that they really hold up well. I have them shaped at 25*-ish with a 3*-ish microbevel.

[David Weaver]

There are a lot of decent chisels out there. A budget consumer who doesnt mind imports can get a bubinga (at least that's what I think it is) handled set of chinese made chisels from wood craft - 8 of them - for $40 sometimes.

A little over a year ago, there was a debate about them and they (WC) specified hardness on them, and I could not resist buying them to see if they were as hard as they said they are. I think they are, but they are an alloy steel, so they hold up really well at 30 degrees and reasonably well at 25.

Still, to be able to get a chisel that has a hardness spec for $5 per, and you can grind the sides down a little to make the bevels more delicate if you want - usable tools have never been that cheap. They are far better than the chinese irwin handled chisels I've seen and tinkered with, at least at the edge, but the ergonomics are a little funny - but they're $5 each, so you don't get to be that picky.

Kind of reminds me that I need to unload them.

I had wondered about the footprint, because they have a wide flat grind down to a delicate bevel on some of them in some pictures, and in some chisels they also spec hardness (which makes it easier to trust that someone is paying attention to them and not just hardening mostly the middle with a quick and poorly calibrated induction hardening and tempering).

[george wilson]

The Sorbys were carbon. I can't re harden or temper HSS. That needs to be done in an inert gas furnace,and the temps are way high for wrapping in stainless foil.

Chinese chisels can be hard,but they can be made of .40% carbon steel,which is at the low threshold of hardenable steel. This means they will be hard,but have poor wear resistance. These are those super cheap sets you see on Ebay,or HF,places like that.

Woodcraft could be getting a better grade of steel in the Chinese chisels they have made over there. You CAN get whatever you are willing to pay for. I have no idea what their bubinga handled sets may be made from.

[David Weaver]

Yeah, they're definitely not 0.4% carbon. They feel just like any other modern chisel. I have seen woodcraft specify some alloys in some thing (like their chisel plane) and have no idea what the alloy numbers are. Maybe they're like those, but they aren't like those dark hand-forged carving tools and they're not similar to the plain carbon steel laminated irons steve knight used to sell that chris scholz gets from china.

I have never had bad luck with any modern chisel that has a hardness spec that isn't 8 miles wide. There was an argument on woodnet back then (before I got banned) and I got them as a curiosity, figured out they were probably as hard as they said they were and then thought "why did I buy these?".

Years of pigging has me in a pile. I've gotta start unloading some stuff so I dont' have to keep trying to figure out where to put it!

[john brenton]

I'm not knowledgeable enough to speak on it in any technical terms, but I do know that:

1. The shape is good for everything except for all but the small tails...but so are almost every other non-DT chisel. Not a problem if you saw out the waste...or I suppose you could grind the sides to whatever you wanted them to be.
2. The balance in the hand is perfect.
3. The backs were flat right out of the box. I think only one chisel required a little more than a polishing.
4. They hold their edge just as well as any chisel I've ever used.

Granted, I've never used the modern high-end, cryogenic, funkadelic super chisels...so I can't really compare there, but I've had no chipping, rolling over, quick dulling...on any of the 7 chisels in the set. As I got them super cheap I haven't worried about abusing them and they've held up to that...so that means something to me. If they were crap I would have chipped them already.





I had wondered about the footprint, because they have a wide flat grind down to a delicate bevel on some of them in some pictures, and in some chisels they also spec hardness (which makes it easier to trust that someone is paying attention to them and not just hardening mostly the middle with a quick and poorly calibrated induction hardening and tempering).

[george wilson]

Narex chisels are still a good buy. From all reports good chisels,and pretty low priced. Narex doesn't make everything cheap. I have a boring head set for my milling machine by Narex,and it lists at about $2500.00. A very nice boring set,too. Extremely high quality.