micro bevel on mortise chisels? Is it a yea or a nay?

[Scott Driemel]

Finally back in the shop after a year and had the oportunity to aquire a set of Narex mortise chisels for my birthday. I'm familiar with the concept of flattening the back and then the 2 sides for mortising chisels, , but haven't got a clue & have been unable to locate it anywhere in my searches, as to whether you put a micro bevel on a mortise chisel. These are pretty big chunks of steel, but mortising is heavy work. I can't figure if they are just best used with a solid primary bevel, or if indeed I should use the micro bevel as well. All my work is in hardwoods, if that made a difference. Been waiting to start on these for some time now but though if possible to get some solid recommendations from the experts here on the site.

[David Posey]

Yes, you want a microbevel. 35 degrees is a good place to start.

[Rob Fisher]

Yes. On traditional pigsticker chisels, which the Narex are similar to though not exactly the same as, a shallow primary bevel, like 20 degrees, then a steeper secondary bevel, like 35 degrees. The shallow bevel allows deeper penetration and the high secondary bevel provides the edge toughness needed for chisels that are struck hard.

I don't believe you should need to touch the sides, unless they are very rough. Typically just flatten the back and sharpen the bevel. If you take too much off of the sides you will change the width. Not a good thing for a mortise chisel.

[Scott Driemel]

Hmmm, just went down to the shop & checked. The stock grind on the Narex mortising chisel set is indeed 25 degrees. I checked aan old set of Sorby mortising chisels I bought used years ago and see they too have a 25 degree primary but someone has (not me) put a (looks like ) about a 2 degree micro bevel on them as well. I have the Veritas honing tool which has a flip switch as you who have them know which increases the bevel by a few degrees? to create a micro bevel. Off the top of my head not sure how many aditional degrees this actually does. If my stock setting is 25 degrees, I'm quite a ways away from any kind of 35 degree micro bevel.

[David Posey]

I just freehanded mine after checking my angle with a protractor. You shouldn't need to do anything to the sides on the Narex as they are trapezoidal in cross section and won't really touch the walls much anyway.

[Scott Driemel]

From what I've heard/seen, it's a good idea to lap the sides of the mortise chisel as well as the bottom. This is in the initial flattening. The bottom edge of the side steel is important (so I've been told) to be at a sharp 90 degree angle to the sole of the chisel. It's bizarre that there isn't more on this. I can find hundreds, yes hundreds of articles on bench chisel sharpening, dozens on doing machine mortise chisel sharpening and set-ups, but hardly a thing on the best "angle of attack" for a hand mortise chisel. (not to mention if they do better with or without a secondary bevel). Frustrating. I appreciate dave's comment regarding the 25 primary but wow, to have the secondary bevel 10 degrees more is well, so different than how I do my other chisels. Maybe for mortise chisels it has to be that much of a difference. Wish I knew. I'll make certain when I do my sides to just ensure they are flat and to not take too much steel off. Okay, now I have to go see if they aren't square edges on the bottom side. You've peaked my cuirosity.

[Jessica Pierce-LaRose]

The trapezoidal sides will help keep the chisel from sticking as it gets driven further and further into the mortise. When you're fairly in, the trapezoidal shape can help scrape away against the walls of the mortise as you rock the chisel back - it can be helpful. No need to make the sides 90 degrees to the back of the chisel - if you really wanted that (some folks prefer that thinking it will help "guide" the chisel - I've never found that to be the case) then you should just have started with a sash mortise chisel or something that began with perpendicular sides.

As far as the secondary bevel, Rob has go it right - having a narrow primary bevel lets the chisel sink deeply into the wood - particularly when you're dealing with these very thick chisels. ( If you think about if you ground the whole chisel to 35 degrees or so, eventually, you'd just be slamming the back of the bevel into the wood after a pound or two) The secondary bevel (it's not really a microbevel - the few strokes worth that characterize what we think of when we say "micro bevel" aren't really going to be effective) helps sturdy the chisel for the heavy work that mortise chisels take - particularly if you're the type to use the chisel for prying. (I'm not - as Roy Underhill said, "there's very little prying in woodworking")

If you're working softer woods, you can get away with a shallower bevel. Too shallow, any you'll see edge failure pretty quickly in harder wood. Same thing you'll notice in the difference between chopping and paring dovetail waste.

Feel free to try it however you want it - while you don't need the razor-sharpest of edges on a mortise chisel, you'll be able to tell pretty quickly if you haven't gotten a steep enough angle.

I've seen chisels for mortising mentioned at 35 degrees in every text I've seen. I've seen a least a couple mentions in magazine articles of the benefits of the shallow main angle and the steep secondary. I've never see it recommended to lap the sides, however.

Mortise chisels are just going to be sharpened differently, because you're using them much differently than other chisels. Don't worry about the micro bevel feature on the MKII (I've had a hard time even getting a proper mortise chisel to fit in my MKII - it's too thick) just sharpen the tip noticeably steeper (careful if you're using waterstones - grind on the pull - when changing the bevel angle this dramatically, it's easy to gouge the stone if you put pressure on the push stroke)

[James Taglienti]

Hi scott,
there are a lot of different methods of work when it comes to sharpening and tuning tools. A mortise chisel is a very simple tool used to stab, pry, and loosen chunks of wood out of a mortise. Worrying too much about lapping the sides, exact bevel angles, etc is not as important as finding a decent balance between edge retention and ease of entry. Most of these chisels have relief angles somewhere letting them move easily the mortise. They are also sized at the fatory so removing any material from the sides changes their width. You are of course free to polish the sides and the back etc but the chisels will work well with little attention to the surface finish. A quick sharpening at the microbevel that the other folks described is all you should need.

Out of curiosity who is advocating the flattening of the sides?

[James Owen]

Yes, you want a secondary bevel. Around 35˚ is typical; with some woods, you might want to go as high as 40˚. For strength and edge retention, I've found that making the secondary bevel about 1/8" to 3/16" wide (more or less) gives good edge retention and is easy to sharpen freehand. YMMV.

[Scott Driemel]

A big thx to all who provided their info. It was an article in one of the main stream magazines that spoke of not necessarily grinding the sides, but I suppose "honing" the bottom edge where the bottom meets the side. (If that is making sense?) It was said to assist the shearing of fibers alongs the side of the mortise when the chisel is struck. Made sense, but I have a hard enough time not poking myself with the sharp end never mind having to worry about a sharp edge on the lower edges as well. I haven't tried to fit these narex mortise chisels into my Mk ll hone yet so the issue of whether they'll fit will be of interest. The Sorby's fit just fine, but the Narex seem a lot taller. I'm not that much of a free-hander yet. I'll put an extra 10 degrees (up to the 35 degree) secondary bevel on these chisels and see how they work. A heartfelt thanks to those who've taken the time to help me out.

[David Weaver]

Honing the sides is fine, but don't try to grind them to 90 degrees. And less is more with the honing of the sides if you're goign to do that. If the grind is fair on the chisels, it's probably a waste of your time.

microbevel or not is something for you to work out for yourself in the shop - try it both ways. There are a lot of variables in how you'll personally work, not the least of which is whether you have the bevel facing the waste side (ala robert wearing) or turned away (I think most folks do the latter) when you're chopping.

[Jim Koepke]

There are a lot of variables in how you'll personally work, not the least of which is whether you have the bevel facing the waste side (ala robert wearing) or turned away (I think most folks do the latter) when you're chopping.

Chuckling a bit at this since when I am chopping in the middle of a mortice the waste is on both sides of the chisel.

FWIW, I do not intentionally use secondary bevels on my blades. The only exception to this is on thick blades that have a big enough bevel to stick to the stone when they are being sharpened.

jtk

[Frank Drew]

I don't believe that you can keep a secondary bevel truly flat if you're doing it freeehand; the human hands and arms aren't able to operate that precisely when riding on such a small area. IMO.

[Jessica Pierce-LaRose]

Lock your arms to your sides, and make your movements with your legs and you core, kind of rocking your body forward and back - much easier to keep things flat that way than to try and move your arms perfectly horizontal. It'll be flat enough.

[Jack Curtis]

No way. My blades are trapezoidal shaped (helps with getting the waste out) and flat bevelled, both Japanese and English, although sometimes I curve the English bevels, that's not microbeveling. I tend to not pry with either as well.

[James Owen]

Exactly how I do it! Works like a charm....

[Kenneth Speed]

I'm with Jim K, I don't put a micro-bevel on anything on purpose. The bevel on mortising chisels is generally pretty obtuse as the chisel is supplied. Why wound you want to make it even more obtuse?


Ken

[Jessica Pierce-LaRose]

I'm with Jim K, I don't put a micro-bevel on anything on purpose. The bevel on mortising chisels is generally pretty obtuse as the chisel is supplied. Why wound you want to make it even more obtuse?


Ken

The Narex mortise chisels the original poster has came to me, at least, with a bevel at 25 degrees. Not stout enough for regular chopping. It's good because it gets metal out of the way and allows the chisel to really sink into the wood, but for heavy chopping (and a bit of prying) the cutting edge needs to be more obtuse.

[Kenneth Speed]

Joshua said, "The Narex mortise chisels the original poster has came to me, at least, with a bevel at 25 degrees. Not stout enough for regular chopping. It's good because it gets metal out of the way and allows the chisel to really sink into the wood, but for heavy chopping (and a bit of prying) the cutting edge needs to be more obtuse."

OK, I'm curious now! I'll check the bevel on my mortise chisels and see what it is. The bevel looked strong enough so I just touched them up and used them with the factory bevel. They seem to work pretty well although the edge does take a beating with the heavy chopping and prying that these chisels endure.

I have the extra strong German mortise chisels sold by Traditional Woodworker and I'm pleased with them. They have really huge handles that can take hard pounding and give the user a lot of leverage and the blades are long and straight sided. The length adds leverage and makes it locate the chisel. It seems some people don't like straight sides but I use a chisel narrower than the mortise (3/8" for a 1/2" mortise for example) which allows me some room for error and generally enough to pare the edges clean after the mortise is cut.

I'll readily admit that chopping mortises by hand is NOT my preferred method and if I have more than a couple I'll do it a different way.

OK, I checked the chisels are ground and sharpened at 30 degrees with no micro bevel

Ken

[Ryan Baker]

Those big mortise chisels from Traditional are great -- I really like mine and will be getting some other sizes. I haven't put a micro bevel on mine yet and haven't had any problems chopping into hard maple. I probably will add the micro bevel eventually. But just because those chisels provide a lot of leverage doesn't mean you should be using leverage. Prying with a mortise chisel is just going to break the tip and isn't necessary anyway.

My Narex mortise chisels have a sharper bevel angle. They just feel like they need the micro bevel, whether it really helps or not.

Cutting a mortise with an undersized mortise chisel seems to just completely defeat the purpose of the mortise chisel and add a lot of extra work. Different strokes for different folks I guess.

[Jessica Pierce-LaRose]

Yeah, the only time I've cut a mortise with an undersized chisel is when I'm chopping a really big one like some of the ones in my bench - at that point it was quicker to bore out the waste with a brace and then pare it clean, but I did have decent luck chopping two 1/4" mortises near to each other and then quickly wacking out the middle to get something like a 3/4" mortise.

I certainly can't do a mortise nearly as accurately using an undersized chisel if the two passes intersect.

[Gary Herrmann]

Ray Iles recommends 20 degree primary and a 35 degree secondary bevel on his pig stickers. Works for me.

[Scott Driemel]

Hmmm, so, if I was to paraphrase some of this info, the suggestions are; 1) for light mortising, the 25 deg primary would be fine for most work.(a secondary bevel is optional) 2) for heavier mortising a sharper angle of say 30 or 35 deg is better for support on the blade. (again secondary bevel optional). Hey. again being new to hand mortising, I'm all for just having to have a primary bevel but it's ahrd not to think "secondary" would be even better! Arrrrgh! I guess some trial & error is the way to go and just see what works for me.

[Gary Herrmann]

I guess some trial & error is the way to go and just see what works for me.

And there's the best advice of all.

[Rob Fisher]

Scott, for mortising with a pigsticker style chisel, I would most definetily use a secondary bevel. Shallow primary bevel, about 20 degrees allows the chisel to penetrate deeper into the mortise. A secondary bevel or about 35 provides better edge retention when using a mallet. If it was a single bevel of 35 degrees, the obtuseness of the bevel would make it considerably harder to get the chisel to penetrate as deep as a 20 degree bevel.

[Kenneth Speed]

Ryan Baker wrote, "Those big mortise chisels from Traditional are great -- I really like mine and will be getting some other sizes. I haven't put a micro bevel on mine yet and haven't had any problems chopping into hard maple. I probably will add the micro bevel eventually. But just because those chisels provide a lot of leverage doesn't mean you should be using leverage. Prying with a mortise chisel is just going to break the tip and isn't necessary anyway.

My Narex mortise chisels have a sharper bevel angle. They just feel like they need the micro bevel, whether it really helps or not.

Cutting a mortise with an undersized mortise chisel seems to just completely defeat the purpose of the mortise chisel and add a lot of extra work. Different strokes for different folks I guess."

Well, I find that I'm not generally satisfied with the cheeks of the mortise if I use a 1/2" chisel to do a 1/2" mortice, for example. I can "horse" the joint into alignment but I don't feel good about doing things that way. By using a 3/8" chisel to cut a 1/2" mortise I (theoretically) leave myself a little room to pare the cheeks smooth. I"ll have a bench chisel or two to hand anyway because I use them to outline the mortise.

I'll readily admit chopping out mortises by hand is not my favorite shop activity by a long shot!

My experience is that mortise chisels,quite literally, take a real beating and the edges need to watched closely or they'll become wrecking bars.

Ken

[Kenneth Speed]

This may be old news to many others but Popular Woodworking has an article by Adam Cherubini about hand chisel mortising in their August issue. In it, Mr Cherubini, suggests paring mortises with pigsticker style mortise chisels and seems to suggest a, "rounded bevel" on the edge. I don't think this is the same as a micro-bevel but I can't say how different it is.

I suppose Mr Cherubini's paring method would work after one has defined the mortise with a bench chisel or two. I think the pig sticker type chisel would be unsuited to this technique because they are, I understand, relatively short but that appears to be what he uses. I, obviously, have never used this method so I can't weigh in on it one way or the other. I did find it interesting that the paring method is supposed to leave , " ...cleaner and more uniform..." mortises, the same thing I was trying to accomplish with my admittedly more complex method.


Ken

[James Owen]

This thread has been interesting and amusing to read.

Interesting, because there is a lot of very good and practically useful information in it.

Amusing, because there is a tendency to over-complicate things. But that is only because my experience has been that, in almost all cases, simpler is better. KISS principle, and all of that.....

*****

Chopping mortises is not that difficult - either in concept or in execution. After all, it's nothing more than a specific sized hole in a piece of wood, made to fit a specific sized tenon. Insert Tab A into Slot B.

While there are certainly other ways to approach things, my preference, when I want to do a woodworking operation, is to see how it was done traditionally, largely because it is a method that has been proven over time not only to work, but to work very efficiently, and also because I happen to be a traditionalist and something of a purist, who likes to do things the old-fashioned way.

The same thing applies to tools. What tool was traditionally used, and how was it set up? In the case of mortise chisels, the traditional pig sticker frequently (not always) has a trapezoidal blade, a 20˚ (more or less) primary bevel, and a fairly wide secondary bevel (1/8" more or less) of about 35˚.

Why was it set up this way? Because it was found, by trial and error over many years (in some cases, hundreds of years) to work. The low primary bevel allows deeper penetration, while the higher secondary bevel helps with edge retention. The trapezoidal shape helps control the cut direction, as well as make levering the chips out easier; both contribute to straight mortise walls. The height of the blade contributes to the strength -- both for chopping and levering, and the bolster efficiently transmits the energy from the mallet strike into the blade and edge. The tapered oval handle helps tell you where the blade is, as well as holding the chisel in place while you use it. The rounded top of the handle absorbs mallet blows without splitting. Taken altogether, it is a truly brilliant design, one that accomplishes exactly what it was intended to do, in a most efficient manner.

Is a pig sticker the only way to chop a mortise with a chisel? Of course not, but once you have overcome the learning curve, it is one of the most efficient and accurate ways to chop mortises by hand.

The same approach works just as well for other tools and techniques.

*****

On one hand, I find it very unfortunate that, since the end of WWII and the advent of affordable decent-quality power tools for the average hobbyist woodworker, there has been a huge loss of traditional hand tool information and technique. On the other hand, we are extremely fortunate that people like Roy Underhill, Drew Langsner, John/Jennie Alexander, Peter Follansbee, Adam Cherubini, Chris Schwarz, Larry Williams, Don Weber, Don McConnell, and numerous others, have undertaken to research, re-discover, revive, and pass on the traditional knowledge that was once handed down via the apprentice system.

And, of course, the internet and forums like this one make it very easy to share that information and discuss the details, alternatives, and experiences using those techniques and tools.

*****

Since this is a hobby for most of us, my nickel's worth is that you should chop your mortises in whatever fashion you prefer and that gives you the best results. The same obviously applies to other woodworking operations. But I would suggest that you also at least take a look at the traditional method(s), and see if they might be of use to you.

Cheers! And Happy Woodworking!

[Joe Bailey]

There is a Peter Follansbee video, in which he chops out a mortise whose side wall is a piece of plate glass. (so that the viewer can see inside the mortise as it's being chopped). He properly credits Roy Underhill with the glass concept. Here is a still showing the primary and secondary bevels on his pigsticker.

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[John Coloccia]

This may be old news to many others but Popular Woodworking has an article by Adam Cherubini about hand chisel mortising in their August issue. In it, Mr Cherubini, suggests paring mortises with pigsticker style mortise chisels and seems to suggest a, "rounded bevel" on the edge. I don't think this is the same as a micro-bevel but I can't say how different it is.

I suppose Mr Cherubini's paring method would work after one has defined the mortise with a bench chisel or two. I think the pig sticker type chisel would be unsuited to this technique because they are, I understand, relatively short but that appears to be what he uses. I, obviously, have never used this method so I can't weigh in on it one way or the other. I did find it interesting that the paring method is supposed to leave , " ...cleaner and more uniform..." mortises, the same thing I was trying to accomplish with my admittedly more complex method.


Ken

I suspect a rounded bevel helps in levering material. With a straight bevel, you will always pivot at the apex of the angle....and on a pig sticker, that's pretty far away. With a round bevel, you have a continuous surface to lever against, potentially making it much easier. I don't know if that's why they used rounded bevels. I've seen enough abused and badly sharpened old tools to know that not everything old timers did was for a good reason, but in this case there's a little advantage to doing it like this.

I do wonder about using an undersized chisel, though. If I wanted to pare my mortises, there's no way I would ever use a chisel to hog out all that material. I would drill out the waste, and then pare it back. I just find that faster than chiseling out waste, and then continuing to chisel the sides. The beauty of a mortise chisel is that it's optimized to rapidly removing the waste while cutting the walls at the same time.